The Little Shop of Horrors recalled "at first they told me it was a detective movie; then, while I was flying back [to make the movie], I think they wrote a whole new movie, more in the horror genre. I think over a weekend they rewrote it." The screenplay was written under the title "The Passionate People Eater". Welles stated, "The reason that "The Little Shop of Horrors" worked is because it was a love project. It was "our" love project." The film was partially cast with stock actors that Corman had used in previous films. Writer Charles B. Griffith portrays several small roles. Griffith's
The Little Shop of Horrors the film entering the public domain. Because of this, the film is widely available in copies of varying quality. The film was originally screened theatrically in the widescreen aspect ratio of 1.85:1, but has largely only been seen in open matte at an aspect ratio of 1.33:1 since its original theatrical release. The film's critical reception was largely favorable, with modern review aggregate Rotten Tomatoes giving the film a "Tomatometer" score of 91%. "Variety" wrote, "The acting is pleasantly preposterous. [...] Horticulturalists and vegetarians will love it." Jack Nicholson, recounting the reaction to a screening of the film, states that