In the DS, both Japanese versions of the PlayStation and Saturn release, and some PC versions of the first Resident Evil game, the cutscene after encountering the first zombie includes a scene where Kenneth's head falls to the floor and rollls towards the camera. The head scene was removed from the other versions, even though his head is still detached from his body.

In later games containing the same scene, such as Resident Evil (2002) and Resident Evil: The Umbrella Chronicles, Kenneth's head remains attached to his body.

There are 3 different versions of the intro sequence for the game.

In the Japanese PlayStation version the intro is done in black and white with uncensored violence, in the French/German PlayStation Director's Cut, along with certain PC versions, it's the same as the Japanese version but in colour.
In the French/German PlayStation Director's Cut, Japanese version and some PC versions, Chris Redfield is smoking a cigarette during the cast section, but it was censored in the other versions.

Along with this, the Japanese version on PlayStation and certain PC versions, Chris Redfield's bad ending shows him smoking a cigarette in the helicopter, but it was censored in the other versions.

A newspaper, which shows a dead body is censored from the Japanese version. The Japanese Sega Saturn version however is left uncensored.

The Saturn version of the game also added a second Tyrant. After the player's first victory over the Tyrant that Wesker unleashes, when attempting to leave, another Tyrant will burst out of its stasis container.

A zombified Albert Wesker can be found in the Battle Game minigame, exclusive to the Saturn port. He is far more durable than other zombie enemies found in the game.

In the Sega Saturn version of Resident Evil, the Hunter Alpha's of the original game were replaced by a variant called Tick, which was a somewhat insectoid looking Hunter with its sickle arms and antennae.