The Cosby Show is an American television sitcom starring Bill Cosby , first broadcast on September 20 , 1984 and ran for eight seasons on the NBC television network , until April 30 , 1992 . The Cosby Show is an American television situation comedy starring Bill Cosby , first airing on September 20 , 1984 and running for eight seasons on the NBC television network , until April 30 , 1992 .