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, Quinn O'Hara and Boris Karloff.
The ghost of recently dead Mr. Hiram Stokeley (Boris Karloff) finds that he has 24 hours to perform one good deed to get into Heaven.
He enlists the help of his long-dead girlfriend, Cecily, to stop his lawyer, Reginald Ripper (Basil Rathbone), and a henchman from claiming the estate for themselves.
The real heirs, Chuck, Lili, Hiram's cousin Myrtle, and her son bring their beach party friends to the mansion for a pool party while Reginald Ripper also employs his daughter Sinistra, and J. Sinister Hulk's slow-witted associates Chicken Feather and Yolanda to help them terrorize the teens, while dopey biker Eric Von Zipper and his Malibu Rat Pack bikers also get involved in pursuing Yolanda for a share of the Stokely estate.
[13] Beach Party regulars Jody McCrea, Harvey Lembeck and John Ashley were also originally announced in the cast[14][15] with Buster Keaton signing to reprise his role as a comic Indian.
Ashley and McCrea did not appear in the final film, the male leads being played by Tommy Kirk and Aron Kincaid, both of whom had worked for AIP before.
[23] Aron Kincaid, who was forced to participate in the film under his long-term contract with AIP, was supposed to perform two musical numbers, but these scenes were dropped.
"[24] (This was a slight exaggeration but several cast members did die soon after filming including Bobby Fuller, Phil Bent, Francis Bushman, and Basil Rathbone.)
The stunt scene of Eric Von Zipper crashing his motorcycle into a pond was used again in the first Billy Jack film, The Born Losers (1967), also produced by AIP.
James H. Nicholson and Samuel Z. Arkoff of AIP were not happy with the original cut of the film and subsequently ordered reshoots several weeks after the completion of principal photography, including addition of a new plot involving an old man who has to perform a good deed in order to gain eternal youth, and a sexy ghost in an invisible bikini who helps him.
Margaret Harford of the Los Angeles Times said the film "has little to distinguish itself from its predecessors beyond the rumour that this beach party romp in a haunted house will be the last in AIP's long proliferating series", further noting, "Old timers give the picture some class.
"[28] Filmink wrote "I can’t call Ghost in the Invisible Bikini a good movie by any stretch of the imagination, but it’s endearing in its goofiness – Nancy Sinatra sings “Geronimo”, it’s always fun to see Boris Karloff and Basil Rathbone (who plays the main villain), Quinn O’Hara is terrific as a short-sighted vixen constantly seducing statues thinking that they’re men.