The movie was titled "The Cheap Detective", according to writer Neil Simon, "because the detective in those old films never got paid! Who paid Humphrey Bogart for finding all those crooks in The Maltese Falcon (1941)? He arrested Mary Astor and sent her and everyone else to jail. Who paid him? . . . The character is always involved in danger not for the bucks but because it's his lifestyle".
This picture was inspired by the box-office success of Neil Simon's Murder by Death (1976), which also starred Peter Falk as Sam Diamond, a spoof of Humphrey Bogart's Sam Spade from The Maltese Falcon (1941). However, Falk's character in this movie, is still a Bogart parody, being a spoof of Bogart's Rick Blaine from Casablanca (1942) as well as being an extension of both the Sam Spade character and Falk's Columbo TV persona as well.
The name of the bar, Nix Place, is a spoof of the bar Rick's Place from Casablanca (1942). Neil Simon claimed that Warner Bros. had saved light fixtures and decorations from Humphrey Bogart's club in Casablanca (1942), allowing them to be reused as props for Charles B. Pierce's Nix Place set. He also claimed some of the original waiters were reused as well.
Madeline Kahn's character uses 16 names: Denise Manderley, Wanda Coleman, Gilda Dabney, Chloe LaMarr, Alma Chalmers, Alma Palmers, Vivian Purcell, Carmen Montenegro, Diane Glucksman, Mrs. Danvers, Natasha Ublenskaya, Sophie DeVega, Mary Jones, Lady Edwina Morgan St. Paul, Norma Shearer, and Barbara Stanwyck. The name used most is Mrs. Montenegro.
In order to cash in on the box-office success of this film's predecessor Murder by Death (1976) (which was a parody of locked-room mystery thrillers), some posters for this follow up (which is different, a spoof of 1940s private eye, film noir and foreign intrigue thrillers) were designed with cartoons of 15 characters (evoking a cast of suspects) situated under a giant headline that read "Who Dunnit?".
The detective partners are named Peckinpaugh and Merkle. Roger Peckinpaugh and Fred Merkle were two well known baseball players in the early 20th century.The piano player is named Tinker. Joe Tinker was a famous shortstop for the Cubs. Other characters include Sgt Rizzuto, Sgt Crosseti, and Lt. DiMaggio, all famous Yankees.