According to Bruce Lee's wife Linda Lee Cadwell, the concept of the series was conceived by Bruce, and he met with the producers for countless hours to shape the show. However, the producers did not offer him the role since they did not feel that the American audience (at that time) would accept a Chinese actor as a lead, and eventually went with the Caucasion actor David Carradine.
Benson Fong and Keye Luke both played as the #1 son in many of the popular Charlie Chan mysteries in the 1930's & '40's.
Keith Carradine appears unbilled as the Middle Caine, a role he would reprise only once, also unbilled, in the episode Chains (1973) during the first season. All other entries in which he can be seen utilize archive footage shot for this feature.
Fifteen different actors from the original pilot would go on to appear in the subsequent series.
Richard Loo here plays Shaolin Master Sun, a character he would reprise in two episodes, Blood Brother (1973) during the first season, and Besieged: Cannon at the Gates (1974) during the third. He would also feature in three other entries, playing three different characters: The Tong (1973), Arrogant Dragon (1974) and The Devil's Champion (1974).