Continuity mistake: When Diane Keaton and Al Pacino have dinner, he gets up, puts on his coat and sits down again. Now watch Diane Keaton's glass: When the camera's on Al Pacino she's holding the stem, but when the camera's on her she's holding the body of the glass. Another mistake is that at the end of the scene the amount of wine in her glass suddenly doubles.
Continuity mistake: When Tessio delivers the bulletproof vest and the fish, Sonny's hands are in one position (one below, one on top of the parcel), a fraction of a second later they are in a very different position (both on top, unwrapping). The parcel is half open while Tessio is carrying it but fully closed when he puts it on Sonny's lap.
Continuity mistake: When Don Vito Corleone gets shot, the camera angle from the side of the car shows Fredo bent over trying to pick up the gun he dropped, but when we see him from the camera angle from above, he's just walking to the front of the car. When the angle cuts back to the front of the car, Fredo is once again bent over trying to pick up the gun.
Continuity mistake: Before Paulie is shot, Clemenza gets out of the car to relieve himself and walks only a few steps away from the car. As Clemenza hears the gunshot, he looks back at the car to see Paulie slumped over the steering wheel, and the car is a much greater distance away, than just the few feet he had walked away from it. As Clemenza walks back to the car, it again takes him only a mere few steps.
Continuity mistake: When they're all deciding whether to wait until the Don is better before making a deal with Sollozzo, the cigar box is closed. The camera cuts away for a second, then back and Sonny closes the miraculously open box. He can't have opened it while the camera was elsewhere, because opening it would have taken the lid right past the camera.
Continuity mistake: In the first scene, the undertaker Bonasera asks the Godfather for help. When the Godfather gets up from his desk, the rose in his lapel is either fresh and straight or slightly wilted and bent in alternating shots. Also, later in the wedding scene, this rose keeps recovering from intermittent spells of withering.
Continuity mistake: Outside the hospital McCluskey punches Michael. A few days after the episode outside the hospital, Michael shoots McCluskey and Sollozzo at the restaurant, but there is no mark on his face where he was hit. Then in Sicily when Michael meets Apollonia for the first time, there is still no mark on his face, but suddenly at Apollonia and Michael's wedding, he has a large mark on his face.
Continuity mistake: When Vito Corleone gets shot, he rolls on his back and his coat opens up to show his shirt. Then we see Fredo sitting down on the nearby steps and crying. In the next wide shot, Vito is lying on the side, totally covered by his coat, and Fredo is sitting farther away than where we saw him before.
Continuity mistake: When Michael Corleone goes to Las Vegas to meet with Moe Greene, watch carefully when Moe sits at the table while continuing his argument with Michael. There's a glass of water that changes places from shot to shot. At one moment, the glass is behind Moe's arm, then in the next shot it's in front. Moe moves the glass at one point, but nevertheless, the glass continues to move from shot to shot.
Continuity mistake: In the meeting of the heads of all families, when Tattaglia asks the Godfather for assurance that there will be no vengeance, we see him leaning back in his chair, waiting for an answer. In the next shot the camera is on the Godfather, and we see Tattaglia leaning back again.
Continuity mistake: At the restaurant, Michael, Sollozzo, and Captain McCluskey have just sat down at the table and the waiter comes over to take their order and pour wine. Sollozzo recommends that McCluskey try the veal, but McCluskey is already eating his dinner. By the way he is using his knife and fork, it is obvious that he is eating an entree, not a salad or an appetizer, even though they just arrived.