Ghost in the Invisible Bikini (according to the film itself and all advertising material) is the seventh (and last) of the American International Pictures (AIP) beach party filmsand was released in 1966. The entire film takes place in and around a haunted house with no beach in sight, with the teenage gang instead cavorting in and around it and the adjacent swimming pool.
Besides the usual bikini-clad cast, random singing, silly plot line, musical guests, and ridiculous chases and fight scenes, the continuity linking this to the other beach films is the Rat Pack motorcycle gang led by Eric Von Zipper (Harvey Lembeck), as well as the appearance of previous beach party alumni Tommy Kirk, Deborah Walley, Bobbi Shaw, Jesse White, Aron Kincaid, Nancy Sinatra, and Boris Karloff.
Pop singer Nancy Sinatra, who was on the rise at the time just before the film was released, has a supporting role and performs one song written for the film; and the Bobby Fuller Four appear as themselves and sing two songs. Claudia Martin, daughter of Dean Martin, co-stars in the film as Lulu. The briefly famous Italian starlet Piccola Pupaappears as herself and sings a song.