Thomas Åhlén starting playing hockey with Hofors IK in 1973 and played there until 1977. From 1977-79, Åhlén was with Leksands IF and from 1979-85 played with Skellefteå AIK before finishing his career with AIK Solna from 1985-90. Åhlén never won a Swedish title, nor did he ever medal at the Swedish championships, his best finish being fourth with Leksands in 1979. Internationally, Åhlén was capped 39 times with the Swedish national team. He won Olympic bronze in 1984 and was a runner-up at the 1984 Canada Cup. He also won a European junior title in 1977. After finishing his sporting career, Åhlén worked as children’s coach with Strömsbro IF.