Continuity mistake: The PBR's roof canvas is damaged by fire after passing another PBR. Later, Chef and Lance repair it with palm fronds. When departing the Do Loung bridge, the roof canvas appears undamaged.
Continuity mistake: Just before the tiger attacks them there's a close-up of Captain Willard's face with a large leaf in front of him to his right. As the tiger lunges he runs several feet to his left. He gets out of the way by moving, but the next shot as he fires his rifle he's back in the same spot again. (00:58:50)
Continuity mistake: As they pull up next to the Vietnamese sampan, Chief Phillips moves the spotlight on top of the PBR with his left hand so it's pointing at Chef as he takes the papers from the fishermen. Thirty seconds later there's a wide shot of both boats as Chef reads the papers and we see the spotlight back to where it was before facing away from Chef even though Chief Phillips doesn't touch it again. (01:35:05)
Continuity mistake: Captain Willard steals Colonel Kilgore's surfboard from the men sitting in the colonel's helicopter. The helicopter has changed since the colonel and his surfboard flew in on it earlier in this scene. The words "Death From Above" and the two crossed sabers that were painted on the front of the helicopter are not on the front of this one. (00:51:20)
Visible crew/equipment: After the man sitting to the right of Roxanne gets up and leaves there's a wide shot of the table with Captain Willard at the right. If you look closely at his hair you'll see the shadows of crew members moving between him and the stage lighting throughout this shot. (02:11:15)
Continuity mistake: When the Medevac helicopter first lands in the Vin Din Dop courtyard there are only soldiers on the left side of it putting the injured man in. In the next shot five soldiers and a Vietnamese woman appear standing on the right of the helicopter who weren't there before. (00:44:05)
Visible crew/equipment: As he gives the captain some water, Dennis Hopper says, "Why would a nice guy like you want to kill a genius?" Look closely at the ladle and you can see the reflections of two crewmember's heads moving in front of the main stage light, one on the left and one on the right. (02:43:00)
Continuity mistake: When the woman tries to feed the rice to Captain Willard he absolutely refuses it and the spoon barely touches his lips before she takes it away. The next time we see his face after he spots the colonel there are two small pieces of rice stuck to the right side of his upper lip as he turns to the right after the woman wipes his face. (02:54:00)