He is regarded as the founder of the Slovenian school of research in algebraic graph theory and permutation groups.

After completing a post-doctoral fellowship at the University of Reading in 1983, Marušič spent a year teaching high school mathematics in Koper.

In 1988, he returned to Slovenia to work at the University of Ljubljana, where he rose quickly through the ranks, becoming a full professor in 1994.

He has increasingly devoted his time to the newer university, where he established the Faculty of Mathematics, Natural Sciences, and Information Technologies (UP FAMNIT).

[3] He is one of the two founding editors and editors-in-chief (with Tomaž Pisanski) of the journal Ars Mathematica Contemporanea.

[4] Marušič is regarded as the founder of the Slovenian school of research in algebraic graph theory and permutation groups.