Elizabeth Taylor was shooting The Only Game in Town at the same time as this film was in production. While that film is set in Las Vegas, Taylor demanded that director George Stevens shoot in France so she could be close to her husband, Richard Burton, who was filming Staircase with director Stanley Donen. This caused the budget of The Only Game in Town to grow higher than most large-scale, high-profile films that Fox was producing at the time. Ironically, the production of Staircase was moved to France to save money.
Rex Harrison reportedly hated the film.
Charles Dyer (who wrote play on which movie is based) named one of lead characters after himself and rearranged letters of his name to provide other lead's character name - Harry C. Leeds.
On-screen credits photographically juggle names of Richard Burton and Rex Harrison so quickly it is nearly (and deliberately) impossible to figure out who is top-billed star without benefit of home video freeze frame.
The original Broadway production of "Staircase" by Charles Dyer opened at the Biltmore Theater in New York on March 2, 1968 and ran for 61 performances.