The theme song was sung by Cyndi Lauper (doing an impression of Betty Boop), but is listed in the credits by a stage name, Ellen Shaw.
According to Mark Mothersbaugh, he would compose the music for each episode just four days before they aired.
The 1st season's Playhouse Gang's characters (Shaun Weiss, Natasha Lyonne and Diane Yang Kirk) were all fired from the show, because of their disruptive behavior on the set.
Throughout the entire series run, the closing credits have never credited Paul Reubens as Peewee Herman, but instead would display the other cast & guest stars first and then would display "and Peewee Herman as Himself".