When Ivan enters the building for the Karate championship at the end of the film, some guys in his entourage (especially the Hispanic-looking man in a white shirt and beige pants) show up as extras in the crowd who are booing Ivan.
When Jason's father is serving beer in the bar, the foam on the top changes drastically several times.
When Jason fills out his dojo application, he is given 11 seconds to complete the form. Dean Ramsey enters the scene and takes the completed form from him.
When Jason hangs his punching bag, he clips it and it drops to the floor. In the next shot, the bag is at head level.
In the opening dojo scene, the American flag on the wall is backward.
The crowd is completely silent in many shots during the karate tournament.
In a wide shot of Jason performing a two-finger push-up, a thin wire is visible above the trees in the background.
Microphones are visible in scenes featuring the abandoned house.
A stage light and the matte box attached to the lens are clearly visible in the Lee house training scenes.
When Ivan kicks the ref out of the ring you can clearly see him land on the safety foam placed outside of the ring for stuntman safety.
The film is set in Seattle, WA. When Scott confronts RJ at the burger joint, several palm trees are visible in the background.
Karate is Jason's lifelong passion. Yet when he sees Kelly for the first time in Seattle, he doesn't know her brother is a national champion who owns his own dojo.
In the final fight, Ivan seems to lose all of his fighting skills as soon as Jason enters the ring. He drops his defense and allows Jason to beat him at will.
When Jason first meets Bruce Lee he greets him as "Sensei Lee". Lee was Chinese, so the correct term is "Sifu." "Sensei" is a Japanese title.