When Lilo is running from the beach to dance class she is wearing a striped bathing suit, over which she puts on her grass skirt before entering the building. When she joins the other children onstage she is still wearing her grass skirt, but she is now wearing a tube top.
When Nani invite Cobra Bubbles into the house there is a pot simmering on the stove. She takes the lid off then turns around, after Lilo walks in they show the stove behind Nani and Cobra Bubbles and the pot has turned into a frying pan.
When Lilo is talking to the Hula teacher about just wanting dance, we can see Myrtle in the background holding her arm. On her wrist is a grass bracelet. When we focus on Myrtle and she says "Eww, she bit me"; the grass bracelet is gone.
During the first hula class, Myrtle clearly has light skin; but as Lilo runs to talk to the group of girls after class, she is as dark as Lilo. Later, when Stich steals Myrtle's bike, she is light again.
When Nani, Lilo, and Stitch come home after the luau, Nani reaches halfway up the wall, turns on the lights, and the sound of the switch flipping can be heard. The light switch can be seen a moment later as she carries Stitch out of the kitchen, but when she tries to carry him out of the house, it has disappeared.
In the scene after Cobra Bubble's first visit, Nani brings
Lilo some pizza in her room. Behind Lilo you can clearly see a neon green star and moon on the right bedpost. Later on, as the lights go out, the star and moon are clearly on the left bedpost. Later still, when Stitch wakes up Lilo with the Duckling book, the star/moon isn't even on a bedpost, it's on the headboard between the posts. After that, the star/moon disappear completely to reappear on the window frame for two scenes.
When Stitch is first escaping the prison ship, the female pilot states that "He's loose on deck C!" and points at a moving red dot. However, the camera then shifts to Stitch, who is still locked in place.
When Jumba is at Lilo's house trying to catch Stitch, at one point he rips the plate rack off the kitchen wall and throws the plates at Stitch who is crawling on the celling. But a while later when Lilo calls Cobra Bubbles for help, the plate rack (and the plates) is back on wall behind her.
During the Scene when Nani is apologizing to Lilo for yelling at her, Lilo is sitting on the left side of her bed holding her Scrump doll. Than Nani picks her up to console her, Lilo casually drops Scrump on the same side of the bed. Yet, when the shot changes, Scrump is now on the far right side of the bed.
Right before Stitch finds the Ugly Duckling book, he picks up three other books. The first two, "Oyster Farming: Is it for you?" and "Fire Eating for Fun and Profit" have their titles printed on the back of the books, and nothing printed on the fronts.
After Stitch destroys the ships power grid at the beginning of the movie, one of the Gantu's deckhands checks on the computer to see if a police cruiser has been taken. How can she be checking the computer when the power has been cut?
At the beginning of the film, the Grand Councilwoman seems not to know the Planet Earth (since she doesn't recognize it and doesn't know it's almost completely covered in water). However, in the end of the film, she claims she has already been on Earth in the Roswell incident, and she has met Cobra Bubbles.