While Umberto Lenzi began the Italian-made cycle of brutal Amazonian cannibal horrors with Il Paese del Sesso Selvaggio and effectively ended it with the nauseating Cannibal Ferox, it was Ruggero Deodato who directed the subgenre's most enduring film.

This popular bloodbath features a fetus ripped from a woman's body, people fed to piranhas and impaled on spikes, a genuine tortoise-flaying, and numerous other indignities, both real and simulated. The plot concerns the efforts of a group of American explorers to discover the fate of a missing documentary film crew.

They receive a scratchy film-reel containing the bloody truth from a tribe of tree-dwelling natives, and the reel's contents make up the bulk of the film. Advertisements claimed that "the crew who filmed it were actually devoured alive by cannibals," yet most of them were spotted alive in future unsavory gore films.