• During the long shot of Mystique driving the boat to the Statue of Liberty, you can see the head of someone below the window. That is reportedly the boat captain, who was in a different place in close-ups.
• When Wolverine's car hits the tree, front window gets smashed out of the car. In subsequent shots, the window is only damaged and is back in its place.
• In the Statue of Liberty, after Toad spits his slime on Jean Grey and he falls, you can see the rope that was holding him up and where it connects on his back.
• Character Henry Peter Gyrich's last name is incorrectly spelled Guyrich in the end credits.
• When Toad is struck by lightning, the lightning hits the pole first, and then electrocutes Toad. While the pole is grounded, there is enough power in a lightning strike that the field would still affect Toad (though not as visibly as shown). In addition, Storm does, after all, have some control over lightning.
• The star on Magneto's father's coat at the beginning changes sides from the left to the right.
• Various differences from the comic books. These are, by policy, not considered errors; it's mentioned here only due to the volume of submissions.
• The amount of sun hitting Senator Kelly in the helicopter scene with him and Mystique.
• When Wolverine is thrown off the head of Statue of Liberty, he stops himself by hanging on his claws; at that moment, they pierce through the head near Jean Gray and Cyclops who are trapped inside near the top. In one of the next shots we can see Wolverine hanging on his claws much lower in the head - somewhere around the ears and the chin of the Statue.
• Crew or equipment visible: The camera is visible in Cyclops' glasses when he is in Logan's room and says, "Oh, and Logan: stay away from my girl."
• When Sabertooth falls off the Statue of Liberty he falls through the metal roof of a boat. Closer examination of the way it breaks and the color shows that this is not metal but thin plywood.
• During the fight atop the Statue of Liberty, Sabretooth throws Wolverine away from the statue's crown. In the next shot, their positions are reversed, with Wolverine's back to the crown.
• When Wolverine swings around the spike on the crown of the statue with his claws, he lands with his right hand held forward, claws unsheathed. In the next shot, his left hand is held forward just before he leaps.
• In one shot, Logan is smoking a cigar and his truck window is up. In the next shot, outside the truck, his window is down. Inside the truck in the next shot, his window is once again up.
• After Magneto has Wolverine magnetically stuck to wall inside the Statue of Liberty's head and says, "Let's point those claws of yours in a safer direction", Magneto makes Wolverine's arms face down across his chest and they're held in place by metal braces. But in the next shot, we see Wolverine's arms are seen folded across his chest facing up instead.
• After the bar fight, Logan drives off; as he stops, the tires leave snow tracks. As he starts up again, and before the snow could have buried them, they disappear.
• The straps inside the Statue of Liberty that hold the skin of copper to the iron frame were originally iron, then were replaced with stainless steel during the refurbishment. At no time were they green as shown.
• When Magneto tells Prof. Xavier that the plastic prison won't hold him and the war is coming, the shot from behind Magneto's head shows his mouth still moving, even though he has stopped speaking.
• When Mystique as Bobby Drake approaches Rogue to warn her away from the school, Rogue clearly mouths the word "Shawn" but her voice says "Bobby".
• Orientation of Magneto's helmet on the desk during the first scenes in the Brotherhood's lair.
• Mystique pushes Senator Kelly back after he yells, and when he lands against the seat we see her right foot wrap around the back of his head. In the next shot, her foot is just starting to move around to his head.
• In early scenes the filmmakers went to some effort to make Cyclops appear taller than Wolverine, but about half way through the film they just stopped, and suddenly Wolverine appears considerably taller than Cyclops (consistent with the difference in height of the actors themselves).
• When Xavier and Magneto are in the plastic prison, the chess pieces on the board change between shots after the guard comes in.
• Stuntwoman Kathryn Anderson's name is misspelled in the end credits as "Kathyrn".
• When Magneto concedes that he has been checkmated and knocks the king over, a pawn that was in the previous view of the chessboard is missing but the knight still holds it to checkmate.
• In the train station, as Sabretooth is coming up behind Storm at the ticket window, he throws the guy behind her out of the way. The line attached to the stuntman is visible in this shot as he is yanked out of the way.
• The chain-link fence door is very "floppy" when Mystique hits Wolverine with it in their final fight.
• When Wolverine stabs Rogue, his claws go through the front and out the back. She heals herself using Wolverine's powers, but there is no blood on the front of her night gown and the fabric is still whole (where the claws went through).
• When Jean is showing the x-ray of Wolverine we can see that his claws run from his elbow to around halfway his hand. This means that it runs trough his wrist, which in turn, as ademantium is indestructible/not bendable, would mean that wolverine would not be able to move his wrist at any given point when his claws are in.
• Near the end Wolverine touches Rogue in hopes to heal her. It finally works, but all of Wolverine's injuries from his fight with Sabertooth reappear. Rogue only takes on other mutants powers for a short while. Wolverine's injuries should not have come back since they were already healed.
• During Logan's nightmare scene in Xavier's mansion, when Rogue walks into the room, his sheets are pulled up to his armpits, but as she approaches the bed and the camera angle changes the sheets move to about his waist, too quickly and too neatly to have been thrown there during camera movement.
• When Logan puts his arm around Rogue while they are on the train, he puts his hand on her shoulder. In the next shot his hand is on her head.
• Wolverine's hands never bleed when the claws come out. Even though he has healing powers, his other cuts always bleed at least initially. Because he doesn't grow scar tissue, his hand should bleed every time.
• Cyclops's laser moves way too slowly. The movement of the laser should be instantaneous as far as all human perception is concerned. Sabertooth is even seen dodging the laser in his first fight sequence.
• When Jean Gray is checking Logan after the fight you can see a pink bra under her jacket. The camera then switches to Logan and when it returns to Jean Gray the bra is missing and her coat closed up.
• Hugh Jackman took cold showers to help him create the character Wolverine's trademark "berserk rage."
• There were three types of Wolverine claws - plastic, wood, and steel and more than 700 individual claw blades were used by Hugh Jackman and his four stunt doubles.
• When in full Mystique makeup, about 60 percent of Rebecca Romijn's body was covered in prostheses.
• Most of the eye effects were done by using special contact lenses that the actors found very uncomfortable to wear. Rebecca Romijn-Stamos (Mystique) could only wear her lenses for an hour at a time and had only 10% vision. Halle Berry (Storm) was supposed to wear opaque white lenses for the scenes where she uses her weather-control powers. However, she found the lenses unbearable, so her eye effects had to be done entirely through CGI.
• Ten Wolverine costumes were built out of thick leather and PVC, and were designed to take a beating. All of them were destroyed to some extent during filming.
• Hugh Jackman had to undergo training from a hand-to-hand combat specialist to learn how to handle the Wolverine claws.
• The control stick that Cyclops uses to pilot the X-Men jet is a CH brand "Flightstick Pro" computer joystick.
• Bryan Singer had an actor dressed in a Spiderman suit confront the actors on set one day as a joke. Realizing that he's in the wrong movie, Spidey backs off (this can be seen as an "Easter Egg" on the DVD edition of the movie).
• Despite being 6'1", James Marsden had to wear platform shoes so that he would appear taller than Hugh Jackman (6'2").
• After knocking Storm down an elevator shaft, Toad (Ray Park) kicks away the bar that was holding the elevator doors open, grabs the bar, spins it over his head and then holds it in an attack posture in the same way he does with the double-ended lightsaber as Darth Maul in Star Wars: Episode I - The Phantom Menace (1999).
• When Wolverine first explores the school he's wearing black pants, no shirt or shoes, and is confronted by mirrors. This echoes Bruce Lee's appearance in Enter the Dragon (1973).
• Many of the X-Men from the comics who don't have major roles in the film appear as minor characters in the school. Among them are: Jubilee, the Asian-American girl wearing a yellow jacket, hoop earrings with sunglasses above her forehead; Shadowcat, also known as Kitty Pryde; Colossus; Iceman, aka Bobby Drake, and Pyro.
• George Buza, the trucker, portrayed the voice of Beast in the "X-Men" (1992) animated series.
• Ian McKellen's character, Magneto, is a Jew who survived the Holocaust. In Apt Pupil (1998), also directed by Bryan Singer McKellen portrays a Nazi who committed Holocaust atrocities.
• When Wolverine complains about their outfits, Cyclops asks him if he'd prefer yellow spandex. This in-joke refers to the fact that the X-Men's costumes in the comics are predominantly yellow spandex. Incidentally, after the sucess of this movie, the costume designs of the comics were changed to a "black leather" design similar to the one's worn in the film.
• After a defeated Storm re-enters the fight, Toad complains, "Don't you people ever die?" This is an in-joke since, in the comics, almost all of the characters featured have "died" at least once, then come back.
• The character Kitty Pryde (the girl who walks through the wall) was originally named after a real-life girl X-Men artist John Byrne knew in Calgary, Canada. When the movie was released there, local media managed to track down the "real" Kitty Pryde.
• Toad was originally a hunchback, but that was changed so as not to interfere with Ray Park's martial arts abilities.
• The sunglasses Cyclops wears are Oakley "X-Metals", more specifically, the "Juliet" style with Ruby lenses. In keeping with the mythos of the comic book character, Cyclops must wear lenses with some form of ruby protection to contain his optic blasts which are uncontrollable without them.
• X-Men creator and executive producer is a man near a hot dog stand on the beach when Senator Kelly comes out of the water.
• The writer of X Men appears as one of the cops near the end.
• The police officer stabbed by Sabertooth in front of the Statue of Liberty was played by D.B. Sweeney, who is a fan of the X-Men and had tried out for the part of Cyclops.
• Michael Chabon was approached to write the script.
• Senator Kelly's line at the beginning of the movie about having a list of known mutants living in the United States is based on Senator Joseph McCarthy's famous speech about having a list of known communists working in the State Department.
• While the WGA credits approbation, several writers involved in writing the screenplay decided to not be credited, and David Hayter received sole credit. The writers who contributed uncredited are: Ed Solomon, Christopher McQuarrie, Joss Whedon, James Schamus & John Logan.
• WWE wrestler 'Kevin Nash' (I) was offered the role of Sabretooth, but he turned it down due to schedule conflicts.
• After the film was completed, the wheelchair that the character Professor Xavier used was sold in an auction to Patrick Stewart's attorney, and then rented back by the production company for X2 (2003).
• Wolverine's line, "What do they call you, 'Wheels?'" was an ad-lib by Hugh Jackman (the scripted line was, "What do they call you, Baldie?").
• James Marsden turned down a role in Soul Survivors (2001), in order to take part in this movie.
• A scene appears in a TV spot for the film, but does not appear in the movie, of an extended talk between Scott Summers (James Marsden) and Professor Xavier (Patrick Stewart) regarding Logan's stay at the mansion. Scott tells the Professor "He's not one of us. There's no way he's going to take orders." Xavier politely replies, "Give him an order worth following. He'll take it." More of this extended scene appears in the official movie adaptation novels and books, but it was cut out of the final film to meet the allowed running time.
• The bar scenes were shot in the same brewery as the concentration camp scenes.
• The last scene shot in Canada as part of principal photography was the first scene in the movie - that of rain falling on mud in the concentration camp.
• Neither Patrick Stewart nor Sir Ian McKellen know how to play chess.
• Angela Bassett turned down the role of Storm, while Aaron Eckhart and Viggo Mortensen were both considered for the role of Wolverine.
• Jada Pinkett Smith was considered for the role of Storm.
• When the project was in development at Carolco pictures, Michael Biehn was the front runner for the role of Cyclops.
• Sarah Michelle Gellar was considered for the role of Rogue.
• Bryan Singer wrote the duologue between Wolverine and Cyclops when Cyclops refers to 'yellow spandex' specifically to have a dig at fans on the Internet who complained about the X-Men's costumes.
• In the Hamilton location (the train station scenes), the director, Bryan Singer, was mistaken for an onlooker, and was harassed by a policeman, not letting him join the production team for some moments.
• In the bar scene, after the fight where Wolverine gains some money, the guy behind the man that accuses Wolverine of cheating is Malcolm Nefsky, the film's best boy grip. Because of the way the scene was filmed, someone was needed to deliver the line, and he was called because no certified "extra" was nearby.
• The last scenes to be shot were the ones where Senator Kelly (Bruce Davison) emerges from water (in Santa Monica, California). They were shot in early May, and the film was released on the last days of July.
• Hugh Jackman got his testicles caught in his harness after a 6 foot jump off the set's Statue of Liberty.
• The Mansion used as the Xavier school, is the same one Billy and his family lived in in Billy Madison (1995)
• Joss Whedon wrote a draft version of the script, but the suggestions he made to fix what he felt were fundamental problems with the film were not incorporated. Only two pieces of dialogue from his rewrite appeared in the final film. One is the exchange when Cyclops doesn't know if Wolverine is an impostor ("Prove it!" "You're a dick"); the other is Storm's "Do you know what happens when a toad gets hit by lightning? The same thing that happens to everything else." which he imagined as a lighthearted, offhand line.
• Numerous actors were considered for the role of Wolverine. Bryan Singer talked to Mel Gibson, 'Russell Crowe (I)' and Edward Norton, while Fox were interested in Keanu Reeves.
• During a scene with Rogue, it is possible to see Bobby "Iceman" Drake's breath even though it seems to be midsummer (an after effect of his ice-powers?). Fans noticed this detail and credited to director Bryan Singer's dedication to the story and the particulars of each character's powers. However, it was a mistake and never noticed nor intended for the film (in fact, the Iceman character is being impersonated by Mystique at the time). The effect was intentionally added to the story of the movie's sequel X2 (2003), however, when Iceman and Rogue share a kiss.
• Senator Kelly calls his aide "Henry" several times and when he asks Magneto what he's done with Henry Magneto replies "Mr. Gyrich has been dead for some time." In the cartoon and in the comics Henry Gyrich was a member of several United States national security agencies, and was responsible for quite a bit of misery in the X-Men's lives, including causing Storm to lose her powers and ordering the creation of one of the many models of Sentinels.
• The very first scene shot for the movie was the World Summit scene on Liberty Island where representatives from each country are greeted. Two of the guests (identified by Bryan Singer as king and queen of Poland) are played by Bryan Singer's father and stepmother.
• Hugh Jackman's physique looks slightly different in different scenes because he was cast 1.5 months after principal photography had started and kept working out extensively while shooting continued.
• Patrick Stewart was the very first mutant to be cast.
• Although he's reasonably tall, 'James Marsden'(I) , who plays Cyclops, had to stand on an apple box to appear taller next to one of the boys in the train station. As a prank, Tyler Mane, who plays Sabretooth, went into Marsden's trailer and set an apple box in his bathroom with a note - "This is so you can reach your sink."
• Similar to Magneto's and Rogue's background segments, segments explaining Storm's and Cyclops' backgrounds (where Storm's background segment involved her changing the weather drastically in her home country in Africa and causing vast damage) were scripted and storyboarded but never shot. There was a brief talk to shoot these scenes while shooting X-Men 2 in order to insert them into the X-Men Special Edition DVD, but the idea was later scrapped.
• Rebecca Romijn's make-up process involved putting on more than 60 self-adhesive prosthetics developed specifically for the movie, followed by air-brushing the blue paint. The make-up team was reluctant in using food coloring for her make-up because of its difficulty to remove, but used it after discovering a new chemical that could very quickly and easily remove food coloring.
• Tyler Mane kept the large black contact lenses in for too long one day and was blinded for a day and had to wear bandages.
• The film was in development at Carolco Pictures in early-'90s, with James Cameron attached to produce. After James Cameron moved on to Spider-Man and Carolco went bankrupt, the rights became available and were purchased by Fox.
• Natalie Portman turned down the offer to play Rogue.
• Bruce Davison was the first actor to be cast.
• Look for James Marsden's platform shoes as he scales the wall at Liberty Island, after leaving the X-Jet.
• The song used for the teaser trailer is "Chinese Burn" by Curve.
• In the first X-Men movie, Halle Berry had the African Accent that Storm had in the comic books; but in part 2, she decided not to use the accent.
• James Caviezel was originally going to play Cyclops but backed out in the end.
• Musician Glenn Danzig, whose muscular physique and height (5'4") almost perfectly matched the Wolverine character portrayed in the comic books, was interviewed for the role of Wolverine. A common myth has it that he was offered a part in the movie, but this confusion occurs largely because Danzig was actually offered the role some ten years earlier - when Carolco held the rights to an X-Men film and was considering a low-budget production. However, due to the high-budget and status of the 2000 production, as well as Danzig's age and relative lack of acting experience, and the requirement that the Wolverine actor be signed to a multi-picture deal spanning several years, it is highly unlikely that Danzig could have won the role in Singer's film. Regardless, a scheduling conflict prevented him from any subsequent pursuit of the role.
• 28 drafts of the script were written, and halfway through those drafts, the writers were still rewriting the whole story every time.
• Jeri Ryan was in the running for Mystique.
• Maria Bello was considered for the role of Jean Grey at one point.
• According to Bryan Singer at Wondercon 2006, he initially approached John Williams to compose the score for the film, but Williams wasn't available at the time because he was scoring Saving Private Ryan (1998).
• In order to keep her look a secret, Rebecca Romijn had to sit in an isolated, windowless room when not required for shooting. To celebrate her last day on set, Romijn brought in a bottle of tequila to do shots with her fellow cast and crew during a break in filming. Unfortunately, that day she happened to be filming the Wolverene/Mystique fight scene, and she threw up blue-colored vomit (from the chemicals in her make-up) all over Hugh Jackman.
• The scene is the train station where the young boy smiles at Cyclops, and Cyclops smiles back was unplanned. The boy was a huge fan of the X-Men, and Cyclops was his favorite. The scene originally called for Cyclops to look at the train schedule, however, according to Bryan Singer, the boy could not stop smiling at James Marsden (the actor playing Cyclops). Finally, during one shot, Marsden just looked back at him and smiled, much to the boys delight. Bryan Singer liked the idea so much, he kept it in the film, and told the actress playing the boy's mother to react the way she did.
• Wary of the risk of starting an expensive franchise that could have died after just one film, Fox's studio executives assigned the film a budget of only $75 million, quite low for a big summer tent-pole release, when the average summer blockbuster budget at the time was upwards of $100 million.
• Wolverine's dog tags are the standard type issued by the Canadian military.
• Rebecca Romijn and Sam Elliot have both played major and supporting roles as different characters throughout the Marvel Universe. Sam Elliot played a major role as General Ross in Hulk, and a supporting role as the Caretaker in Ghostrider. Rebecca Romijn had a major role as Mystique in all 3 X-Men movies, and played a supporting role as Joan (Frank's neighbor) in The Punisher.
• Near the end, during the Wolverine/Mystique fight scene, there is a moment where Mystique kicks Wolverine in the groin. At that moment, there is a metallic 'ping' (similar to the one in the beginning when the man in the cage match punches wolverine's fist), which is probably an 'in-joke' to wolverine have 'balls of steel' (or in this case, adimentium).
• Bryan Singer cast Halle Berry as Storm after seeing her performance in Introducing Dorothy Dandridge (1999) (TV).