He made his debut forCroatia in an October 1990friendly match against theUnited States, coming on as a 58th-minute substitute forAljoša Asanović, and earned a total of 19 caps, scoring 3 goals. Since Croatia was still part of Yugoslavia at the time, his first 3 games are unofficial. Mladenović participated atUEFA Euro 1996 and his final international was at that tournament in the quarter finals against eventual winnersGermany.[4]
Following his retirement from playing professional football, Mladenović started a career as a referee, as well as a manager. Since 2002, he managedNK Žminj, Rijeka, NK Halubjan, NK Cres andOrijent.