Revealing mistake: A second martian saucer crashes but it is the same as the first but reversed (look at the striped awning to the store window for both shots). (01:23:25)
Continuity mistake: When the school bus is leaving Pacific Tech, the name "Southridge" is painted directly on the front of the bus. When Dr. Forrester finds the wrecked vehicles in the city later in the film, the name "Southridge" is now painted on a separate wooden sign that he picks up.
Visible crew/equipment: When the martian space ships first appear you can see the wire suspending the models. You can clearly see the wires every time you see a martian or martian space ship.
Revealing mistake: After Forrester picks up the school bus sign, there's a shot of a Martian machine blasting at a bridge. Looking closely, the light poles can be seen through the machine, showing the model was matted over the background.
Revealing mistake: In the first scene of the crashed meteor, on the extreme left of the scene where the smoke is, it seems to be billowing up from behind a stage wall, as there is a definite vertical line and a gap between the smoke and the left edge of the frame.
Continuity mistake: Look closely when the Martian "spaceships" make their first appearance, underneath are three electro-magnetic legs supporting it meaning they walk rather than fly, much like the tripod war machines in the original book, yet after this scene they can't be seen again. The studio opted to forgo the use of this special effect after this particular shot. (This is best seen on the DVD version of the film.)
Continuity mistake: The aeroplane flying the atomic mission against the Martian invaders is seen on the display console before the radar beam detects it.
Visible crew/equipment: When the radio reporter is broadcasting before the first attack, he is speaking into a microphone connected to the radio truck. After the Martians begin shooting, he dives into a small ravine. You can see his microphone cord being manipulated off camera to the right where it is being cut by a crew member.
Continuity mistake: The Sherman tank (30126777) disintegrated in Scene 141 is the same one that Ann Robinson & Gene Barry dodged in the later bug-out sequence.
Continuity mistake: One of the reporters refers to a Martian attack on Rangoon, India. Rangoon (now Yangon) is in Burma (now Myanmar), and while Myanmar had been governed as part of India under the British Raj, it achieved independence in 1948.
Revealing mistake: As Forrester is easing up to check the Martian arm, a second Martian flyer crashes. As it does, you can tell that it is a re-use of the first one crashing, but flipped so that it's hitting left side first rather than right side first.
Other mistake: In the War Room, the Martians' movements are demonstrated on a chalkboard, but push pins easily go into it a moment later as if it were cardboard or sheet rock.
Other mistake: In the farmhouse, when Sylvia looks out and sees movement, she claims it was too dark to see. However, the Martian was lit up enough to be seen from a distance, and details on it were seen.
Other mistake: When the people in the bunker are watching the Reverend walking, there is a distinct meshing of two separate scenes.
Continuity mistake: When the Martian probe is being demonstrated in the lab, as it first comes on, it's slightly tilted. As the camera is in wide shot, the probe is straight up.
Character mistake: On several occasions, scientist (Clayton Forrester) refers to the impacting objects as "meteors". Any scientist knows (or should), that when a meteor impacts the the ground, it becomes a "meteorite".
Continuity mistake: When Dr. Forrester whacks off the aliens' spy camera, it looks like it's virtually destroyed when he bends down to pick it up. Later in the lab when they power it up, it's in pristine condition.
Revealing mistake: When the military starts firing, not only do you see the wires holding the saucers, but the "electromagnetic shields" can be seen as glass or plastic domes, as the studio lighting is reflecting in them.
Factual error: The Marines that arrive at the landing site are said to be from El Toro, but El Toro was a Marine Corps Air Station; it would not have had the infantry, artillery, and armored units that arrive at the site.
Continuity mistake: From the time the army first attempts to destroy the Martians until the movie's end, Sylvia wears the same blue dress. Despite sheltering in an army bunker, being in a plane crash, jumping into ditches, running through woods, escaping a demolished house, and evading a frantic mob, her hair remains perfectly coiffed and her dress stays clean and undamaged.