Continuity mistake: When Norman is getting ready to test himself, he lies down on the bed, fastens himself in and the doctor goes to the computer. However, when it shows him being brought in to the chamber he has several electrodes connected to his chest and head. (00:15:20)
Suggested correction: At first the electrodes are beside Norman's head. While the doctor is fixing him in place, at one point camera focuses on his face. Later when he's stepping back for the PC, the electrodes can actually be seen stuck on his body. You can see them if you have an HD copy. So the camera focusing on his face is indicating that the doctor's doing whatever necessary for the process.
Continuity mistake: When Peter shoots his web at his bedroom lamp and pulls it across the room, it smashes against the wall and breaks. But when Aunt May is talking to Peter from the door seconds later, the lamp is back on the dresser in one piece. (00:32:15)
Continuity mistake: When Mary Jane is being mugged by four men, Spider-Man throws two of the men into two windows behind Mary Jane. The shot switches to Spider-Man beating up the other two guys. When it cuts back to Mary Jane the two windows are intact. (01:17:00)
Continuity mistake: In the final battle, the blood on Spider-Man's chin and under his nose keeps disappearing and reappearing. (01:42:15)
Continuity mistake: When Jameson is flipping the pictures of Peter's first batch of photographs, you can see that the 3rd picture he looks at changes into an entirely new photograph, when he puts it down. The one he's looking at is Spider-Man on the side of a building, but when it's on the desk it's Spider-Man kicking a thug in the face. The one he then looks at changes too - it was about to have a bit of sky on the left, but then turns into a photo of a street from above, with no sky visible. (00:58:45)
Continuity mistake: When Peter is talking with Mary Jane outside the diner where she works, watch the positioning of the shadows in the background. As the camera shoots from Peter's point-of-view, the sun is casting shadows up the street. When the shots change to MJ's point-of-view, the shadows are pointing down the street, as if the sun had just moved ahead several hours. (00:57:30)
Continuity mistake: When Spider-Man is chasing the crook with the gun, the crook shoots 7 times through the roof of the car. Shortly afterwards you can see 9 bullet holes in an overhead shot. As the scene moves along there is another overhead shot (just after Spider-Man jumps the bridge) - no bullet holes. Seconds later the bullet holes return. (00:44:40)
Continuity mistake: When Peter Parker confronts Uncle Ben's killer in the warehouse, after Parker slams him through the glass windows in the door, the killer drops his gun and pulls out a knife. After he is disarmed of the knife, Peter kicks him up against the wall. At this point the killer has the gun back in his hand. (00:47:50)
Continuity mistake: When Peter is drawing up ideas for his costume the hand is that of comic artist Phil Jimenez, current artist of Wonder. Phil Jimenez is right handed and Tobey is left handed. In one of the cuts the pen is in Tobey's left hand but it shows him drawing with his right. (00:31:25)
Continuity mistake: In the cafeteria scene, Mary Jane slips on some spilled orange juice that causes Peter to catch her. A short while later when Peter gets up to leave the cafeteria, running away from her enraged boyfriend, the spilled orange juice is not there. (00:22:15)
Continuity mistake: In the final cemetery sequence, Peter and Mary Jane square off for a little heart to heart, with her touching his face tenderly with her black leather gloves. The camera intercuts between front views of both: in hers, her fingers are touching his ear lobe, in his, they are a inch below his ear lobe. In one quick cut of hers, the hand has disappeared completely, then in mid-sentence as they cut back to Peter, it's there again. (01:49:20)
Continuity mistake: When Peter is taking out the trash, and begins talking to Mary Jane, as she walks toward him you can see her underwear sticking out above her pants. As the shots change, this underwear seems to appear and disappear. (00:29:24)
Continuity mistake: During the World Unity Festival when the Goblin attacks, there is a shot of Peter tearing off his shirt exposing a costume that is low cut at the neck. However, in the scene when Spider-Man and Mary Jane kiss in the rain, the costume comes halfway up his neck. (01:17:55)
Continuity mistake: When Peter is talking to Mary Jane outside the diner, the same man wearing a flat cap is walking behind Peter 3 or 4 times. First when Peter says "so you're acting now?", then when he talks about Harry not living on earth, then again when Mary Jane walks off. (00:55:15)
Continuity mistake: During the World Unity Festival, as the balcony first collapses, a blond woman and a man are running to get out of the wreckage. But in the next shot, the same couple just stand under the falling balcony looking up and Peter uses webbing to pull the standing-still couple to safety. (01:04:15)
Continuity mistake: When Spider-Man is taking snapshots of the armored car burglary, one of the burglars says "watch the street". As the camera snaps you see them pointing rifles or machine guns towards the sky and when Spider-Man lands on them to dispatch them, the weapons are gone... (00:58:20)
Continuity mistake: In the scene just before the final fight between the Goblin and Spider-Man, Spider-Man gets knocked through a wall and rolls right up against another wall, but when the bomb flies in as he's getting to his feet, he's suddenly in a much more open area with no wall anywhere near him. (01:40:55)
Visible crew/equipment: When Peter stands up after being bitten by the spider, there's the reflection of the cameraman with headphones on the television set behind him. (00:10:00)
Continuity mistake: When Peter Parker is chasing the school bus for the first time, the bus stops and it is entirely visible that there is nothing in front of the bus. When the camera is switched to the inside of the bus to show Peter stepping inside to apologize to the bus-driver, however, a tractor-trailer suddenly appears only yards from the front of the bus (visible through the windshield). Some road markings also appear. (00:03:50)
Revealing mistake: When Peter is jumping from building to building after he first learns he has powers, you can see that he is jumping over the same alley over and over, only taken at different angles. The clotheslines (and the shadow of them on the wall) is a good pointer. (00:25:10)