Just before this show premiered on September 20, 1978, Robert Urich briefly appeared (in a backdoor pilot) as Dan Tanna at the end of Charlie's Angels (1976) season three, episode one, "Angels in Vegas". Supposedly, Dan Tanna was a friend of Charlie and Bosley.
Robert Urich packed on 40 pounds of muscle for the role of Dan Tanna. His weight boosted from a skinny 180 pounds to a solid, muscular 220 pounds.
The name "Dan Tanna" was taken from the name of a favorite restaurant of Aaron Spelling on Santa Monica Boulevard in West Hollywood, California. Dan Tana's Restaurant is still in business as of November 2008. On May 14, 2020, Michael Gotovac---its bartender for the past 50 plus years---died of complications from COVID-19.
Most of the hotels that are shown in the opening credits aren't there anymore. These include the Frontier, the Stardust, Dunes, The Desert Inn, and the Sands,
Aaron Spelling's writers based "Dan Tanna" on long time Las Vegas detective Eddie La Rue, who passed away in 2020 and was still running his Las Vegas agency until he passed.