An All-EuroLeague Team selection on two occasions, he played with Borac Čačak, Crvena zvezda, Partizan, Budućnost Podgorica, TAU Cerámica, Pamesa Valencia, Panathinaikos, and PAOK, which he joined in September 2008.

[1] Tomašević started his career in 1990 with Crvena zvezda,[2] where he stayed for 5 years, winning 2 Yugoslavian League championship titles.

[6] He was also a member of the FR Yugoslavia team that won the gold medal at the 1998 FIBA World Championship in Greece.

[13] In October 2015, Tomašević was appointed as an acting Secretary General for the Basketball Federation of Serbia.

[15][16] In March 2019, the Federation put forward a nomination of Tomašević for the president of the FIBA Europe.

[17] On 25 May, Tomašević lost the 2019 FIBA Europe Presidential elections from Turgay Demirel, who was re-elected.

[18] He became a member of the ruling populist Serbian Progressive Party (SNS) in May 2023[19] and was its candidate in the 2023 parliamentary election.