Continuity mistake: The commandos are in the river, at night and they are setting the charges on the bridge, the variety show is going on at the same time. Between the British soldiers heads and the roof of the auditorium, the Japanese soldiers are standing in bright sunlight.
Continuity mistake: When Allison arrives at the island in his raft, he sticks out his head to take a look. When his face is seen, his hair is completely dry, but when his back is seen as he prepares to go ashore, his hair is soaked.
Continuity mistake: According to one of the characters, the firing squad is drawn from the 3rd Battalion of the 701st Infantry Regiment, the same regiment as most of the other characters. However, all the members of the firing squad (except the officer and sergeant, who are credited characters seen elsewhere in the film) have "710" on their collar patches. This can be seen when the sergeant, who has "701" on his collar patches, is briefing them.
Continuity mistake: The Sergeant (played by Karl Malden) is on leave with his family when the car needs water. His daughter (played by Natalie Wood) gets out and refills the water. During the conversation, Malden is bare headed, then immediately after he has a hat on.
Continuity mistake: The flowers Sgt. Killian places in his helmet's netting change from fresh to wilted several times as the scenes change.