Continuity mistake: After Woody tosses the string lights to Andy's toys at the window Mr. Potato Head hangs onto the end of it, but in the shot from behind Andy's toys when Woody's shaking Buzz's arm and imitating his voice, we see the outside of Sid's window and the string lights have vanished, then they reappear.
Revealing mistake: When Woody grabs hold of Buzz and uses his "karate chop action" while they walk backwards to the open door, as Woody says, "Sorry guys, dinner's canceled," in the wideshot of all of Sid's toys pay attention to the chair and table at the right side of the screen. What we're supposed to be seeing is the swivel chair with four legs/wheels (and the red toolbox resting on the seat) that's positioned in front of the table's angled wood two-by-four legs. But we don't see that. What we do see is the swivel chair and table all blended together - the seat and legs of the chair are somehow behind both sets of table legs and the chair's backrest is in front of the table, which doesn't make any sense.
Other mistake: While Sid's toys are working with Woody to get Scud out of the house, just as Hand-in-the-Box is holding the doorknob we can see the screw mounted on the latch's hasp below the loop - which really doesn't make any sense, but as Hand opens the door the screw has suddenly vanished from the hasp and is now properly mounted on the doorway's loop plate, where it's meant to be. If the screw were really mounted through the hasp, the door could not be opened.
Other mistake: It's been mentioned that Sid sets his clock for 8:25 and it goes off at 7:00. Here's some more errors for Sid's crazy clock physics. When Woody is saying "Psst" to Buzz from inside the blue plastic basket, the clock on the wall says 6:25, yet the alarm clock next to Buzz says 6:55. It goes off 5 minutes later and after Sid takes Buzz out of the room, the clock on the wall has changed to 3:10. When Woody is talking to Sid's toys a minute later, the clock now reads 10:00. The maximum amount of time that passed between the already wrong 3:10 and the 10:00 is 5 minutes. You can tell because Sid wanted to launch Buzz strapped to the rocket ASAP and Woody wanted to rescue Buzz from his current strapped-to-a-rocket state very fast. (00:56:45)
Continuity mistake: When Woody and Buzz are at the gas station and the big truck pulls in, Woody falls limp to the ground. The truck pulls over him, and stops with its tires an inch from his head. In fact, the brim of Woody's hat sticks up into the space between the two tires. In the next shot when Woody scrambles out from beneath the tires, his head is directly under the tire to our right. (00:31:40)
Continuity mistake: When Andy goes to his room to get Molly, he lowers the side of her crib in order to get her out, picks her up, and walks out of the room. In the next shot of his room, the crib side is back up. (00:03:13)
Continuity mistake: The blue blanket in Molly's crib repeatedly vanishes and reappears within the same scenes, such as when the batteries are put back into the baby monitor Woody shouts for everyone to return to their positions, in the overhead shot of the room the blanket's gone, but is soon back in its place.
Other mistake: During the scenes in Andy's room, when characters are standing near the window beside Andy's bed, and also on both the interior and exterior sides of the window behind the desk, we can see the same markings/scratches/chipped paint on their white lower sash rails, though the marks on the exterior side of the window behind the desk, are actually opposite from the other marks.
Continuity mistake: When Andy has Woody slide down the banister there's a green/white striped rug directly in front of the door, but when the area of the floor in front of the door can be seen from the living room such as when Andy shouts, "Score," the rug is gone, then it reappears when Andy rushes back upstairs to get Molly. (00:02:40)
Continuity mistake: During the earlier scenes in Andy's room Molly's bottle is beside the lamp on the small wicker dresser near the crib, and it disappears and reappears, such as when Buzz wants to prove he can fly he stands on the bed's footboard and the bottle is gone, but it reappears when he lands on the race track. (00:19:00)
Trivia: Originally, Toy Story was going to be about a bear in a toy store. However, the animators decided it would be hard at the time to animate fur for a bear, so they eventually changed the story to what it is now. They kept the bear design, you can see him on the shelf when Woody has his staff meeting. That same bear went through some design changes, and became Lotso from Toy Story 3. (00:06:55)
Continuity mistake: At 09:21 on BluRay disc, is the scene where Woody is instructing the army man to go downstairs. You can see in his left hand there is a set of binoculars and in his right hand is a pistol. In the very next shot (at 09:26) you can see the binoculars in his left hand, but the pistol has disappeared from his right hand, enabling him to salute Woody. A few shots later (09:33) we get a good look at the army man. The pistol is still missing. We also get a look at the holster, which is empty. There was no time for the army man to put the pistol in the holster between shots, and it would technically be moulded to his hand anyway. (00:09:20)