The full names for Wishbone and Mushy are George Washington Wishbone and Harkness Mushgrove III.

Clint Eastwood was twenty-eight when the series began, although his character was supposed to be nineteen.

Although Eric Fleming was the show's star, recently issued DVD packages prominently feature Clint Eastwood due to his later fame.

Eric Fleming (Gil Favor) drowned in Peru while filming a movie. He was forty-one-years-old.

The Mexican helper was named "Hey Soos". The actual spelling of his name is "Jesus", which, in Spanish, is pronounced "hey soos". There would have been letters of outrage if the character was named "Jesus".

The theme for the show was performed in The Blues Brothers (1980).

Clint Eastwood (Rowdy Yates) and George Kennedy (George Wales) starred in Thunderbolt and Lightfoot (1974) and The Eiger Sanction (1975).