Continuity mistake: In the scene where Peter Parker is fighting on a train he tells the last man standing 'not my board', the last man is black but after hitting Parker and the board breaking the next shot is one of the guys he has already knocked down who is white fighting him after the board breaks.
Continuity mistake: Just when Peter tries the web launcher the tables and chairs on the street change number and position through shots: They are arranged parallel to each other and have the following amount of chairs: First table has 3 chairs, second 2, third 1 and fourth 2. In the close-up, all tables have 2 chairs; the first three tables are parallel, yet a fourth one is behind the third table. Peter also knocks down a table or chair which appears standing in the final shot.
Continuity mistake: During The Lizard's attack on the bridge, he throws the car with Doctor Ratha in off a bridge. Peter then catches the car with a web. Yet as soon as he notices The Lizard, not only is the web not in his hand anymore, but there's no sign of it hanging over the bridge either. Then the web and car reappear in the wide shot where Peter swings over to get the boy out of the car.
Continuity mistake: In the scene at school when Gwen invites Peter to have dinner at her house, Peter initially removes both earphones when Gwen talks to him, but when Gwen asks about the bruise in Peter's eye and the camera angle shifts, the right earphone is still in his ear.
Continuity mistake: When Peter throws the trophy out of the window during the fight between him and The Lizard, we can see that it breaks up and the damage of the trophy is all next to each other. But when he throws Gwen out of the window in a web, the damage from the trophy is at least a few feet away from each other.
Continuity mistake: When Peter is looking through his father's file in his bedroom, Uncle Ben comes in and starts playing with a Rubik's cube from Peter's desk. When he sets it down, the top and middle row are red and the bottom row is white. Shortly afterwards, when Peter is researching Doctor Connors on his computer, the top and middle rows are suddenly white and the bottom row is red (not fully solved, as another listed mistake claims).
Continuity mistake: Inside the school lab, the Lizard walks to Peter on the floor and a stool next to him suddenly appears for him to pick up.
Continuity mistake: In the scene when Peter Parker goes back to his Aunt & Uncles house after his first Spidey-training session, he raids the fridge & freezer. When confronted by his Aunt & Uncle, the freezer door is slowly swinging open, but in the next shot, the freezer door next to his Aunt & Uncle is closed.
Continuity mistake: In the scene where the lizard and Spiderman are fighting in the sewers, the lizard scratches Spider-Man's chest, causing tears down the front of his suit and chest. He actually scratches straight down his chest, but from then on, whenever Spiderman's chest is shown the scratches are diagonally across him.
Continuity mistake: During the scene where Spider-Man is unmasked he splits an assault rifle in half, trips a man, then drops the two pieces on the ground. The scene switches to a long shot and Spider-Man can be seen still holding the two pieces of the weapon in his hands. The pieces are out of his hands in the immediate following shot.
Continuity mistake: When Gwen visits Peter at the end of the movie, you can see that the glass door with the house number "36" painted on it has been replaced from when he broke it earlier in the movie, and it looks brand new. Once she leaves and he turns to Aunt May, the numbers have returned to their earlier weathered and peeling state.