In 1969 Slim Smith commenced recording for Prince Buster and Coxsone Dodd's Studio One label, the main rival to Duke Reid. His Studio One recordings brilliantly highlight his passionate, soulful voice, which had an almost manic edge, and confirm him as one of Jamaica's greatest singers. His hits from this period include "The New Boss", "Hip Hug" and "Rougher Yet", many of which were later compiled for the album Born To Love. In 1967 he formed a new version of The Uniques, and commenced his association with producer Bunny Lee. They topped the Jamaican hit parade with "Let Me Go Girl", but after recording one album, Absolutely The Uniques, Smith left the group, staying with Lee to concentrate on a solo career.
He had a hit almost immediately with "Everybody Needs Love". An album of the same name quickly followed, as did many further hits. By 1972 personal problems led to him being detained at Bellevue sanatorium.
Smith died in 1973. Unable to gain entry to his parents' house, he broke a window, badly lacerating his arm. He bled to death before he could receive treatment. His death stunned Jamaica. Still widely regarded as one of Jamaica's great vocalists, his enduring popularity has resulted in the reissue of the bulk of his work.