Lani Kai was born on the island of Oahu and attended Punahou School in Honolulu. After serving briefly in the U.S. Marines, his first performance break was The Don Sherwood Show in San Francisco, California. He played conga for Lionel Hampton in Las Vegas and joined numerous Hawaiian groups and jazz combos. Besides drumming, he also sang and played bass.
At age 24, Kai was picked for the Adventures in Paradise television series. He sings and plays guitar with the Chick Floyd Orchestra on the Decca record Island Love Songs, which features the theme song from the show.