The role of Sheila Shea was originally written for Sandy Dennis. Co-star Paul Dooley was seriously allergic to cats though. When cat-lover Dennis would come to the script readings with up to five cats at a time, he was briefly hospitalized. The role was then offered to Shelley Duvall, who had worked with director Robert Altman on six pictures, but she turned it down. As a result, Allan F. Nicholls then re-wrote the role of Sheila Shea from an earth mother type to the young singer-groupie played by Marta Heflin. Both stars had appeared in the director's previous film A Wedding (1978) which had premiered the previous year in 1978. Duvall and Altman would collaborate on a motion picture one more time the following year with Popeye (1980).
Actor Paul Dooley did not find out he had been cast in the film until a friend told him that it was mentioned in show-business trade-paper "Daily Variety".
According to 'DVD Talk', "[Director Robert] Altman purposely kept 'A Perfect Couple' a little ragged [i.e. low-budget and without big names]. He wanted his lead actors to be more like normal people than big movie stars".
The name of the band was ''Keepin' 'Em Off the Streets".
The movie features twelve musical numbers which were designed to interweave in the story like the music pieces had done in director Robert Altman's earlier film Nashville (1975). Altman would later direct a full feature film musical with The Company (2003).