Petar Prepelić was born in Varaždin, where he completed primary and secondary music school at the Music School in Varaždin in the class of prof. Stjepan Rukljić. In 2006, he studied trombone at the Academy of Music in Zagreb, where he graduated in 2011 in the class of prof. Šime Vulelija. 

During his studies, he participated in the work of numerous orchestras; the orchestra of the Croatian National Theater in Zagreb, the Varaždin Chamber Orchestra, and the Dubrovnik Symphony Orchestra, with which he participated on a tour in Indonesia. 

During his studies, he won the 1st prize at the State Competition in Varaždin in 2006 with the highest number of points in the entire trombone discipline, and performed at the final concert at the Croatian National Theater in Varaždin. 

In 2011, he began teaching at the Music School in Varaždin as a trombone and chamber music teacher, where he and his students achieved numerous results at national and international competitions. (HDGPP – state competition, Svirel – Slovenia, VWB – Varaždin, Davorin Jenko – Belgrade). 

Since 2016, he has been participating in the organizing committee of the Varaždin Woodwind&Brass international brass competition. In March 2023, he is a member of the jury in the trombone discipline at the Slovenian national competition TEMSIG. 

During education, and later, during his pedagogical work he participated in numerous master classes; Branimir Slokar, Carsten Svanberg, Dietmar Küblböck, Dede Decker. He is an active member of the experimental orchestra “NuSynergetic orchestra”, Buzzers quintet, Marko Prepelić quintet.