The rats used in the film were brought in by animal trainer Moe Di Sesso and the rodents had previously appeared in ¡Escalofrío! (1971) and Ben, la rata asesina (1972).
Cast and crew members took advantage of the Beverly Boulevard laundromat location and actually laundered their clothes while scenes were being filmed.
The characters of Louise (the alcoholic librarian) and her wheelchair-bound father later appear in 13 pasos al terror (1980), which was also written by Tony Crechales and George Edwards. In this film, the roles were played by Luana Anders and Peter Brocco, in the other, by Carrie Snodgress and Ray Milland.
According to director Curtis Harrington, 'The Killing Kind' barely saw a release. The problematic distributors cut a deal where the film would only be screened in a few cities in the United States. Other distributors showed an interest in the film but, since no records were kept of where the movie had already been screened, it never secured further theatrical distribution.
The original actor who had been hired to play Terry dropped out at the very last minute. John Savage landed the role the day before filming began.