Spencer Tracy was originally cast as Lancey Howard but poor health forced him to withdraw and he was replaced by Edward G. Robinson.
Sharon Tate was replaced in the film by Tuesday Weld after Sam Peckinpah was fired by producer Martin Ransohoff.
Mitzi Gaynor campaigned for the role of "Lady Fingers", but it ended up going to Joan Blondell. Rumors are abound as to why Blondell got the role, with the most common being that Gaynor and Ann-Margret did not quite get along.
According to an article written by Michael Wiesenberg of Card Player Magazine, "the odds of the two hands appearing in the same deal in the climactic scene are worse than 45 million-to-1."
Director Sam Peckinpah insisted on changing an early expository scene in which a girl in her underwear is massaged with a vibrator. He removed the vibrator from the scene altogether and had the girl lie naked but completely covered with a fur coat. Producer Martin Ransohoff was unhappy with the shift in tone and fired Peckinpah.
Final film of Harry Wilson.
This is the second movie in which Edward G. Robinson plays a gambler that features a straight flush in diamonds. Smart Money has the final credits superimposed over this hand, which is also the final hand in this movie.