Piranha

Steven Spielberg viewed the film prior to its release and enjoyed it so much that he convinced Universal Studios to drop a lawsuit against New World Pictures. The studio had initially sought an injunction to prevent the film's distribution, alleging that it was a blatant parody of Jaws (1975).

When the speedboat races across the lake, a shot from the perspective of the water skier shows the tow rope hanging completely slack. In the immediate surrounding shots, the boat maintains a high speed that would require the line to be under significant tension to support the skier.

The FBI warning at the end of the credits ends with the phrase "So There." Producer Jon Davison used the same joke for the FBI warning in his later picture "Airplane."

Cut in Finland for K16/cut 3 min 18 sec! The cuts include: 1.The death of the boy's dad is shortened. 2.The death of Dr. Hoak is shortened to that point, that we lose almost every shot of the piranhas ripping his flesh. 3.The piranhas attack on the children has lost lots of footage; tons of close-ups of the piranhas ripping the children's flesh, and a piranha attacking on the male camp counselor. 4.The death of Betsy is less graphic. 5.When the piranhas attack on the guests in The Lost River Lake, the beginning of the sequence has lost several killings done by the piranhas. 6.After Dick Miller's line We've got a situation down here, we don't see a very grisly corpse (a'la Rob Bottin) floating in the water, nor the piranhas eating tons and tons of people, and the by-standers watching (this scene is cut almost TWO minutes!). 7.The piranhas attack on Paul (Bradford Dillman) under water lasts much lesser time. NOTE: The Finnish video version re-release in the 90's (above on the right) passed surprisingly uncut with a K16-rating! The US DVD (a part of the "Roger Corman Classics" series) is uncut (the image being presented full screen, which is the director's preferred aspect ratio for the movie), rated 'R', and contains some nice extras.