For the scene in which Chainsaw (Michael Berryman) cuts an outline of Stovitz in the fence, Berryman was asked to perform the stunt but he initially refused, fearing that it was too dangerous. However, as stand-in crew member prepared to rev up the chainsaw, Berryman realized that the chain had been attached backwards, so he intervened before the crewman was seriously injured.
During a rehearsal for the Battle of the Bands sequence, Marc Jackson launched into a windmill spin and accidentally punched Pia Zadora's stand-in in the eye with such force that knocked her to the floor.
Originally the crew had intended to make the sea monster bleed, but gore was deemed inappropriate for such a lighthearted film so at the last minute they substituted bubbles.
Unlike the bulk of the cast, Craig Sheffer and Tom Nolan were hired for their acting abilities and had to lip-sync to prerecorded songs. The experience inspired Nolan to switch professions, he started his own band and eventually gave up acting to pursue his music career.
RHEMA's bass player, Bobby Freedman, didn't appear in the movie because he gave a weak screen test and they only needed five band members. Tom Nolan portrayed the sixth alien because the filmmakers wanted a "real actor" to play the alien leader.