Set in the swamps, presumably in the deep South, Attack of the Giant Leeches is a far cry from an episode of True Blood. This one is a so-bad-it's-funny creature feature from the 1950's by infamous schlock producer Roger Corman. In its favor, the acting is quite good. The characters and believable and there are actually a number of good scenes in the film. However, the giant leeches look like black plastic garbage bags with giant white suction cups sewn on them. The excellence of Them! (1954) is NOT here. These monsters look like those designed for an Ed Wood film. Bride of the Monster comes to mind.
If you like cheese, and lots of it, this movie might actually appeal to you. It's definitely the kind of stuff they showed on late night monsterfests while I was growing up but it's not something I'm too wild about as an adult. Attack of the Giant Leeches could have actually been a decent film if they had spent a little more money on the monsters. It's a shame because this film actually has some potential it never reaches.
For more info check out the film's entry in IMDB.