For the 1974–75 season the club hired a professional coach Živko Stakič and became Slovenian champions in 1977.

Just before the breakup of Yugoslavia, Rudar became the Slovenian champion for the second time in 1991.

In the 2007–08 season they finished first and thus achieved a promotion back to the first league.

The club's highest finish was third place on four occasions, the last time in 2014, when Mate Eterović, Rudar's striker, also became league's topscorer.

Their biggest success was winning the Slovenian Cup in 1998, when they lost first game away to Primorje, but then won 3–0 in front of home crowd in the second leg.