Continuity mistake: In the scene at Strangways', an older woman is talking on the radio. Then a shot shows a younger woman's unblemished hand operating the radio controls. (00:04:40)
Continuity mistake: When professor Dent throws the gun down it lands on the edge of the bed cover - almost on the floor, but in the next clip it is in the middle of the bed cover. (00:55:40)

Visible crew/equipment: The camera's shadow is visible on the ground as the car goes off the cliff in the car chase when Bond is headed to Miss Taro's house. (00:48:55)
Continuity mistake: At the airport, Leiter gets into a 1961 Chevrolet Impala pillared sedan which changes to a a 4-door pillarless sedan during the ensuing car chase. (00:18:00)
Continuity mistake: At the end of the movie Bond and Honey are in a small boat when Felix Leiter comes in a bigger boat and gives them a tow. When Bond sits next to Honey he sits on her right hand side. In the next shot he is on her left and in the next shot he is on her right, and back again, etc. (01:44:10)

Continuity mistake: When Bond turns on the lights after Professor Dent has arrived, his cards on the table have been messed up - compared to when he put the cards down five seconds earlier. (00:55:10)

Continuity mistake: Bond enters his room and spots Sylvia Trench playing golf. As they talk, she raises the golf club. When the angle changes, she holds it down and raises it again. (00:15:10)

Continuity mistake: In the famous casino scene in the beginning of the film Bond smokes a cigarette, but in the cuts between him and Sylvia Trench he sometimes holds it in his hand and sometimes in his mouth. (00:07:55)
Revealing mistake: In the scene where Bond is crawling through the pipes and then descending carefully to a lower level, a strange sound is heard and he begins to slip. As soon as the shot changes before this sound, we can see that it is a stuntman and not Sean Connery. (01:36:00)
Other mistake: At the end of the film when Bond and Honey are rescued in the small boat, Felix walks to greet them. What is strange though, is that there is no mention about where Quarrel is, even though Quarrel and Felix were good friends. (01:43:50)

Visible crew/equipment: In the first scene, after the "3 blind men" have killed the man, there is a clear reflection of a spotlight on the black car, and at least two men visible - a cameraman and what I believe could be director Terence Young. (00:04:05)
Audio problem: When Bond goes in to see M, you can see Bond speaking just after he sits down. His lips move quite a lot, but there is no sound. (00:10:45)
Audio problem: When the radio controller in London says "Hello, W6N. Report my signals", his lips don't move. (00:05:10)
Continuity mistake: When Bond gets into the car at the airport he is sitting behind the driver (left side of rear seat). In the next shot, he is sitting behind the front passenger seat (right side). In a later shot he is again sitting behind the driver (left side again). (00:18:25)
Revealing mistake: During the sequence when Bond is crawling through the tunnel at Dr. No's complex, the tunnel walls wobble. (01:32:00)

Continuity mistake: When Bond and Honey get out of the water after Bond killed the soldier and after they clean themselves in clear water, Honey's shirt is dry, when it was completely wet before. (01:09:15)
Continuity mistake: During the 'You've had your six' scene, the cigarette in Bond's mouth disappears after he kills Professor Dent. (00:56:30)

Continuity mistake: One of Bond's traps in his room is his briefcase; he puts talcum powder on it. When he is done he sets the case down on the right side of the table. To the left is a mirror and by the mirror is an assortment of perfume bottles and a shaving bag. When he returns, the contents on the table are reversed exactly, and the perfume bottles are replaced by a magazine. (00:24:25 - 00:40:20)
Visible crew/equipment: In M's office you can see a boom light reflecting off a painting above the mantelpiece. (00:11:35)

Revealing mistake: When Bond and Honey are made to take showers to clean them of any remaining radioactivity, they are meant to be naked. When Honey gets out of the shower a man holds a towel up for her, but if you look closely you can see that she is wearing a flesh-colored swim suit. (01:16:45)