He started playing bass as a private study. He has played in a few bands which have been mostly from the metal genre. Before Nightwish he played in Nattvindens Gråt, just like Tuomas Holopainen. He joined Nightwish for their second studio album, Oceanborn. Holopainen asked the band's manager, Ewo Rytkonen, to tell Vänskä to leave Nightwish some time after the release of Over the Hills and Far Away, when he felt that the musical differences between the two men were posing a threat to the band. He was soon replaced by Marco Hietala, former bassist of Sinergy. Vänskä has played in the jazzband "Root Remedy" ever since he left Nightwish. A few years later Sami and Tuomas have become friends again, although Sami never returned to Nightwish. Sami used a natural finish Warwick Corvette and a white Spector bass guitar during his time in Nightwish.