Anthony Hopkins helped scare Jodie Foster by improvising some of Lecter's lines.
When filming phonecalls it is standard practice to film both sides separately and have the actors pretend they're having a phone call. At the end of Silence they hooked up the phone to the phone network and had Hopkins call from the set of another movie across the country. When Jodie Foster picks up the phone and Hopkins speaks back to her the look of surprise on her face is genuine.
Executive Meddling: There was not going to be Hannibal Rising, except execs told Harris someone else would write the book if he refused.
Silence was initially put together at the behest of Gene Hackman, who planned to direct and star as Hannibal Lecter. When he left the project, Robert Duvall was considered for the role. Dustin Hoffman and Robert De Niro are also rumored to have been in the running. Michelle Pfeiffer was Demme's original choice for Starling, and her refusal cleared the way for Jodie Foster. Mickey Rourke was offered the part of Jack Crawford and turned it down.