Buddy Hackett auditioned to do the voice of Paulie, but lost to Jay Mohr who did an impression of Buddy Hackett. Buddy Hackett does appear in the film in a small role as Artie, the Pawn Broker, and during his scene Jay Mohr also appears in person as Benny.
Animal stunt coordinator Boone Narr arranged seven separate bird casting calls, involving over 38 species. Blue-crown Conure parrots were deemed best, and 14 of them were used in the production, different birds with different personalities fitting into different scenes. For scenes that were too dangerous for the live parrots, or needed complex facial expressions in close-ups, an animatronic Paulie created at the Stan Winston Studio was used.