Tseng played centre for the Yulon Dinos of the Super Basketball League (SBL) and was one of the most dominant inside players of the league. Having led the new-born league in shot blocks in 6 of its first seven seasons, the skilled centre has also been an efficient play maker for Yulon. With his contributions at both ends of the game, the Dinos ascended to three consecutive SBL championships from 2004 to 2006 where Tseng Wen-Ting was named back-to-back most valuable player for the second and the third championship series they won.
As one of the rare mobile players taller than 2 metres in Taiwan, Tseng has also served as starting centre for the Chinese Taipei national basketball team since his national team debut at the FIBA Asia Championship 2001. At the FIBA Asia Championship 2009, Tseng helped Chinese Taipei to a fifth-place finish while averaging 10.4 points and 4.7 rebounds per game. The fifth-place finish was Chinese Taipei's best finish in the tournament since the turn of the century.