In the backwaters of the swampy Florida Everglades (actually somewhere in California), giant mutated leaches – looking much like men in cheap costumes – kidnap a bunch of poor white trash, stash them in an underwater cave and suck them dry. Not much action, not much excitement, but the abject cheap, sleazy trashiness of the poor white trash does have its appeal.
Cult fave Bruno VeSota (the occasionally perported director of the truly great artsy oddity Dementia [1955 / full film], among other things) plays Dave Walker, a fat storeowner accused of killing his sexy, two-timing tramp wife Liz-Baby (a hubba-hubba Yvette Vickers, Playmate of July 1959), who is actually serving as dessert in the leeches' cave. The nominal heroes of the film do the most damage to the flick, combined they don't even have the charisma of a waterlogged Kotex. The term square-jawed applies well to local game warden Steve Benton (Ken Clark), who decides to solve the mystery of the disappearing white trash with the assistance of his gal Nan (Jan Shepard) and her dad, Doc Greyson (Tyler McVey). And while the leeches never get them like you wish they would, the Italian movie industry did get a hold of Clark in the 1960s: he eventually sashayed his manly-haired, fit-and-slim bod through a series of much more entertainingly bad Eurotrash spy flicks.
The brief sight of the various dead slowly drifting up from the depths of the Everglades is relatively effective, but in general the water scenes (all obviously filmed in a swimming-pool) are amazingly dull. A slow 62 minutes but definitely more fun than cleaning house or doing homework; had the focus of the film remained on the inbred inhabitants of the Everglades rather than the clean-cut and educated, Attack of the Giant Leeches would have been much more fun.
Leo Gordon, who supplied the script, didn't do much better a year later with The Wasp Woman (1960).