"Blood Bath" had a complex and troubled production history, marked by various cuts and reshoots. In 1963 Roger Corman had co-produced a Yugoslavia-made spy thriller called "Operation: Titian", but the film was deemed unreleasable. Corman purchased the rights to another film and assigned writer-director Jack Hill to write a new script. This time, it was a horror film that incorporated the previous footage from "Operation: Titian". Hill wrote and directed numerous horror sequences that were edited into the film, and it was re-titled "Portrait in Terror". Still unsatisfied with the completed product, Corman hired Stephanie Rothman to film additional sequences that were also added. This cobbled-together feature was given a brief theatrical release by American International Pictures under the title "Blood Bath", with screenplay and directorial credit jointly shared by Hill and Rothman. An additional version of the film was made for television and re-titled "Track of the Vampire".