The film's alternative title, "99 and 44/100% Dead", parodies the famous Ivory Soap advertising slogan, "99 - 44/100% Pure". In Great Britain, where the soap advertisement was unknown (and where Ivory Soap was not obtainable), the film - after first retaining its American name for the initial several weeks of release - had its title hastily changed to the more mundane "Call Harry Crown"; this did nothing to improve its box-office performance.
The pop art in the film's credits and promo materials was inspired by the work of pop-artist painter Roy Lichtenstein.
When John Frankenheimer was asked why he made this movie in a 1983 interview, he said: "I don't know. I guess I just wanted the work. I never really had a grip on that film. I didn't know what the hell it was. I knew it wasn't a comedy. I guess I thought it was a parody."
John Frankenheimer had directed several box-office flops in quick succession (at least one of them, "The Fixer", a very expensive film), and told an interviewer very frankly that his reason for directing this film and "French Connection II", which was his next film, was simply that he thought he required two box-office hits back-to-back to restore his "bankability" and to retain his eminence and power as a film-maker. In the event, both these movies proved to be very poor box-office performers, and Frankenheimer never really regained his one-time position as a top director.