Continuity mistake: In the scene in which Hugh Marlowe and his fiancée are on the alien ship, speaking with the aliens, his arm is over her shoulder when shown from the front, but down and he is about a foot away from her when shown from behind. The shots alternate back and forth, front and behind, so that the mistake is fairly obvious. (00:37:50)
Continuity mistake: As the alien's speak to them inside their spaceship, Dr. Marvin stands next to Carol. In the next shot from behind he has his arm around her waist. (00:40:15)
Continuity mistake: The alien's speak to Carol, Dr. Marvin and the others and show them a Navy Destroyer on their video screen firing on an alien spaceship. If you look closely the guns on the ship are not aimed at the alien spaceship. (00:40:35)
Continuity mistake: The alien's show a Navy Destroyer being destroyed by their death rays. Later as it explodes we see the remains of an aircraft carrier. (00:40:40)
Continuity mistake: The Motorcycle cop that is taken up into the alien spaceship with them asks, "What team has won the most World Series?". When he asks the question he takes his hat off which leaves a dark impression on his forehead, in the next shot it's gone. (00:41:40)
Continuity mistake: There's no smoke inside of the alien spaceship but if you look closely before the motorcycle cop fires his gun, smoke from a previous take can be seen swirling above their heads. (00:42:30)
Continuity mistake: As they speak to the aliens inside the spacecraft look closely as the motorcycle cop draws his gun twice before he shoots at the aliens. (00:42:45)
Continuity mistake: The motorcycle cop looks up at the alien's Infinitely Indexed Memory Bank and the front of his hair is combed up into a pompadour. In the previous shot it was combed down. (00:43:00)
Continuity mistake: At the Pentagon Carol and Dr. Marvin speak to the generals and one of them holds a pipe in his right hand. In the next shot he's holding the pipe in both hands. (00:46:15)
Continuity mistake: As Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin the engineer to the right of them turns on the generator. In the next shot the lighting has changed and the the shadow of Dr. Marvin's head appears on the pillar behind him. (00:47:00)
Continuity mistake: Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin. Before he fires it the device is moving, than in the next shot it's still. (00:47:05)
Continuity mistake: As Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin they're all staring at it. In the next shot they're looking at the cement block before it's destroyed. (00:47:05)
Continuity mistake: Maj. Huglin walks in as Dr. Marvin works on the high frequency ultrasonic gun and says, "Hello". Another engineer works to right of them and in the next shot he disappears. (00:47:40)
Continuity mistake: Maj. Huglin walks into the lab as Dr. Marvin works on the high frequency ultrasonic gun and all the equipment behind them is lit up. In the next shot it's not. (00:47:40)
Continuity mistake: Dr. Marvin tries out the new improved magnetic interference unit and invites Prof. Kanter to be the first one to shoot it. He walks over to Prof. Kanter standing in front of the gun twice between shots. (00:49:30)
Continuity mistake: Dr. Marvin tries out his new improved magnetic interference unit and an alien craft is spotted flying around inside of the Belmont lab above their heads. Before the craft takes a dip down at them they're standing on the right of Dr. Marvin's magnetic device, but when we see them again they're standing on the left of his device. (00:50:20)
Continuity mistake: After they've destroyed the alien craft spotted flying around inside of the Belmont lab, Dr. Marvin and the others decide to pack up and leave. Even though the sound has been edited out, the car and truck are already running with their headlights on before anyone gets into them. (00:51:50)
Continuity mistake: Dr. Marvin and the others stop the car and watch the alien spaceship that shows up landing outside the Belmont lab. At first the car is parked on an angle then in the next close-up shot it's on level ground. (00:52:00)
Continuity mistake: As Prof. Kanter is incinerated by the alien's beam we can see the shadows cast by the leaves of the trees move before our eyes between shots. (00:55:00)
Continuity mistake: Prof. Kanter is incinerated by the alien's beam and his cane falls down next to him. The next time we see his smoldering body the cane has been moved and is now touching a tree to the right of the screen. (00:55:05)