In the murky swamps of the Florida Everglades, a local love triangle turns deadly. When the brutish Dave Walker catches his wife Liz with her lover, his jealous rage drives them into the swampy depths. But they don’t escape—they vanish, pulled under by something monstrous.
Soon, more locals disappear, their bodies found drained of blood. Game Warden Steve Benton (Ken Clark) launches an investigation, skeptical of the wild tales of creatures lurking in the bayou. His search leads him to a horrifying discovery: an underwater cave inhabited by intelligent, giant leeches who are dragging victims down to feed on them slowly. Benton must rally the terrified townsfolk for a dangerous underwater confrontation with the bloodsucking monstrosities. This desperate fight for survival against a grotesque natural horror makes Attack of the Giant Leeches a quintessential 1950s creature feature.
