Squirm was heavily edited for its appearance on Mystery Science Theater 3000 in 1999. Among the many scenes cut from the film was the scene of Mick trudging through the swamp, the conversation between Mick and Alma, the worms graphic attack on Roger, the gruesome fate of Mrs. Sanders, and the climax where Roger crawls after Mick and attempts to bite him.
This movie was initially rated R by the MPAA and released theatrically in that form in the US. Shortly after this initial theatrical release, the US distributor, American International Pictures, made some minor cuts to the picture and re-submitted it to the CARA. This new cut of the picture received a PG-rating and, subsequently, was also released theatrically by A.I.P. No additional edits were made specifically for the U.S. video release. The R-rated version has a slightly longer shot in the shower in the beginning of the film, and a slightly longer shot of the worms burying into Roger's face.
The current MGM re-release VHS is rated PG and the DVD is rated R. The R-rated version is one minute longer than the PG-rated version.