When Raymond Burr missed several episodes due to illness, he was replaced by several guest attorneys who were played by Bette Davis, Walter Pidgeon, Hugh O'Brian, Michael Rennie, and Mike Connors.
During the series' original run, Raymond Burr was accosted in public by a woman who demanded to know: "How come you never lose?" To which Burr dead-panned: "Madam, you only see the cases that I try on Saturdays."
Due to illness, Ray Collins only appeared in a few episodes after the 1960 season. He had contracted emphysema brought on by years of smoking, and he also was beginning to forget his lines; because of this he was forced to leave in the middle of the seventh season. Despite the fact that Collins was no longer on the show, it was decided to keep his name in the credits not only to help keep his spirits up, but to allow him to keep getting medical benefits from the actors union. Sadly, he died in July 1965, just prior to the start of the show's final season.
Perry Mason author Erle Stanley Gardner appeared in the final episode, The Case of the Final Fade-Out (1966), uncredited as the second judge.
In at least one episode Perry Mason used a car phone. Although he would have to call the operator first and they were considered radios and not phones, they were in fact the first phones used in cars.