When De Palma was originally considering either Pacino or Dreyfuss for the role of Jack he was also considering either Julie Christie or Dyan Cannon for the role of the prostitute, Sally.
Mike Nichols had spent six months looking for the right girl to play the part of Bobbie. He had considered and rejected Dyan Cannon.
Cannon auditioned for the lead role, but Ali MacGraw ended up playing that role.
Dyan's agent gave her a choice of appearing in the Donn Knotts comedy and securing a five picture deal with Universal Studios or appearing as Alice in the comedy "Bob & Carol & Ted & Alice". She wisely chose the latter and earned a Supporting Actress Oscar nomination.
Did you know that Dyan Cannon was not the only choice for these movies? (click to learn more)