Other blood is actually Bosco chocolate syrup.

The zombie hand that Tom (Keith Wayne) hacks up with a kitchen knife was made of clay and filled with chocolate syrup.

When the zombies are eating the bodies in the burnt-out truck they were actually eating roast ham covered in chocolate sauce. The filmmakers joked that it was so nausea inducing that it was almost a waste of time putting the makeup on the zombies, as they ended up looking pale and sick anyway.

The gas pump was not bolted to the ground when the actress who played Barbra, Judith O'Dea, runs into it at the start of the film. She did it with so much force she almost tipped it over on the cameraman.

One of the working titles for this film was "Night of Anubis". Anubis is the god of embalming/mummifying in the ancient Egyptian (Kemetan) religion.

According to George Romero, ‘Night of the Living Dead’ was originally ten minutes longer but the distributor pressured him to cut it down.

The word "zombie" is never used. The most common euphemism used to describe the living dead is "those things," mostly by Cooper.

The main house did not have a true basement but a dirt potter's cellar, and thus had no long staircase leading down to it. Because of this, the basement scenes were filmed in the editing studio's cellar.
 
Some of the groans made by S. William Hinzman when he's wrestling with Russell Streiner in the cemetery are authentic. During the struggle, Streiner accidentally kneed Hinzman in the groin.

During the filming of the cemetery sequence, shot on two separate days, an unexpected accident caused a fast change of script. The car driven by Barbara and Johnny into the cemetery was actually owned by the mother of Russell Streiner. Unfortunately, sometime between the two filming sequences, someone ran into the car and put a dent in it that would easily be visible on camera. George A. Romero rewrote the scene so the car would come to a stop by crashing into a tree.

In the scene where Ben is nailing wooden boards to the door, small numbers can be seen on them. These were written on the backs of the boards so they could be removed and replaced in between shots, preserving continuity. Some numbers are visible because some of the boards were nailed on backwards.

Tom Savini was originally hired by George A. Romero to do the makeup effects for this film. The two were first introduced to each other when Savini auditioned for an acting role in an earlier film that never got off the ground. Romero, remembering that Savini was also a makeup artist (he had brought his makeup portfolio to show to Romero at the audition), called Savini to the set of his horror movie. However, Savini was unable to do the effects because he was called to duty by the US Army to serve as a combat photographer in Vietnam.