Harmon Johnson is the photographer for a small pornography ring that uses deception and blackmail to coerce its models into performing. Although Harmon is complicit in the crime and takes a cynical attitude to the proceedings, he treats the models more kindly than the rest of the gang.

His current model, Sandy, is nearing the end of her career and begs to be released from her service. Lang, the leader of the operation, agrees on condition that she will procure and help manage new models to continue the cycle. Sandy agrees and her first victim is a naive young girl named Kim, who wishes to save money to go to college. Harmon gets her hooked on modeling by overpaying for some relatively tame "shoe" ads that show off Kim's legs. When she comes looking for more work, Harmon entices her with doing more explicit photos. During this activity a helper, Larry, snaps even more explicit photos and the group blackmails her into doing further work.

Meanwhile, Marie, another model, grows tired of the threatened and actual violence and talks about going to the police with Sandy. Larry and Ajax, a thug and pornographic performer employed by the gang, overhear this and Ajax kidnaps Marie off the street, takes her to a motel room and rapes and beats her severely. When he leaves, Marie calls the police.

Kim is distraught at her situation, but Larry and the gang convince her that it will all be behind her if she agrees to one more day of shooting. However, during the shoot, Ajax continues to menace the girls and threatens to rape Kim. Finally having enough, Harmon intervenes on the girls' behalf, killing Ajax with a baseball bat. Realizing that this will cause the police to investigate, Harmon gives Kim all her negatives and other material and tells her to run away.

During a police interrogation, Harmon is then unexpectedly saved by Sandy and they decide to get married.

Hearing of the encroaching police, Lang makes a run for it, but is pursued until he runs into the ocean and, cornered, shoots himself. In the dénouement, Sandy counsels Kim to pretend it was all a dream.

• William Kerwin as Harmon Johnson (as Thomas Sweetwood)
• Allison Louise Downe as Kim Sherwood (as Vickie Miles)
• Lawrence J. Aberwood as Lang (as Lawrence Wood)
• Sandra Sinclair as Sandy (as Sandy Sinclair)
• Mal Arnold as Larry
• Craig Maudslay Jr. as Ajax
• Christy Foushee as Marie (as Toni Calvert)
• Doug Brennan as Carl
• Christina Castel as Cindy, the model
• Edward Mann as Mr. Sherwood
• Lou Youngman as Dave, punk in diner
• William Caulder as Joe, punk in diner

In his autobiography, David F. Friedman wrote that Scum of the Earth was shot in six days, just two weeks after filming on Blood Feast had ended and was filmed in most of the same Miami and Miami Beach locations as in the previous film. It was filmed in black-and-white not to save money, but to intentionally give it a dirty look, "like an old, scratched 16 mm stag film."^[2] Friedman had the idea of promoting the film a week before its showing by giving theater audiences comic books of the story.^[2]

Allmovie wrote, "Unintentionally funny and poorly photographed, this film certainly has its moments for connoisseurs of bad cinema, but others will find it tawdry and dull."^[3]

Something Weird Video released Scum of the Earth on DVD with The Defilers (1964) on 20 February 2001.^[1] It is also available on the Arrow Video Blu-ray release of Blood Feast (1963) as a special feature.

• List of American films of 1963

• Scum of the Earth! at IMDb  
• Scum of the Earth! at AllMovie