He represented Yugoslavia at the 2000 Summer Olympics for the men's 1500 metre race.
Radomirović ran the men's 1500 metres at the 2001 IAAF World Indoor Championships in a time of 3:46.36.
In 2002, Radomirović ran the men's 1500 metres at the 2002 European Athletics Indoor Championships in a time of 3:54.40.
In July 2005, Radomirović made a return to international competition, running the men's 1500 metres at the 2005 Mediterranean Games in a time of 3:48.08.
Just a month later, he ran the men's 1500 metres at the 2005 Summer Universiade in a time of 3:48.41.