 Robert De NiroRupert Pupkin | Rupert Pupkin |
 Jerry LewisJerry Langford | Jerry Langford |
 Diahnne AbbottRita | Rita |
 Sandra BernhardMasha | Masha |
 Shelley HackCathy Long | Cathy Long |
 Frederick de CordovaBert Thomas | Bert Thomas |
 Ed HerlihyEd Herlihy | Ed Herlihy |
| LLou BrownBand Leader | Band Leader |
| LLoretta TupperStage Door Fan | Stage Door Fan |
| PPeter PotulskiStage Door Fan | Stage Door Fan |
| VVinnie GonzalesStage Door Fan | Stage Door Fan |
| WWhitey RyanStage Door Guard | Stage Door Guard |
| DDoc LawlessChauffeur | Chauffeur |
 Marta HeflinYoung Girl | Young Girl |
| KKatherine WallachAutograph Seeker | Autograph Seeker |
| CCharles KaleinaAutograph Seeker | Autograph Seeker |
| RRichard BaratzCaricaturist | Caricaturist |
 Catherine ScorseseRupert's Mom (voice) | Rupert's Mom (voice) |
 Cathy ScorseseDolores | Dolores |
 Chuck LowMan in Chinese Restaurant | Man in Chinese Restaurant |
 Liza MinnelliLiza Minnelli | Liza Minnelli |
| LLeslie LevinsonRoberta Posner | Roberta Posner |
| AAlan PotashnickMan at Telephone | Man at Telephone |
| MMichael KolbaMan at Telephone | Man at Telephone |
| RRobert ColstonMan at Telephone | Man at Telephone |
| RRamon RodriguezMan at Telephone | Man at Telephone |
| CChuck CoopMan at Telephone | Man at Telephone |
| SSel VitellaMan at Telephone | Man at Telephone |
 Margo WinklerReceptionist | Receptionist |
| TTony BoschettiMr. Gangemi | Mr. Gangemi |
