Zeljko Marasovich was born in Zagreb, Croatia. He studied piano, organ and theory of music at the Zagreb Academy of Music. After graduation he continued his studies in Rome at the St. Cecilia Conservatory of Music, under Mo. Fernando Germani. At the same time Zeljko started performing and giving organ recitals throughout Europe, United States and Asia. Some of his most memorable recitals took place at Notre-Dame Cathedral in Paris, Tchaikovsky Conservatory Hall in Moscow, St. Petersburg Philharmonic Hall, Riga Cathedral in Latvia, Gewandhaus in Leipzig, St. Ignatius in Rome, Brucknerhaus in Linz, etc.

In 1985 Zeljko Marasovich moved to the United States and continued his studies at USC’s Thornton School of Music, where he graduated under prof. Ladd Thomas. He had a long standing association with Pepperdine University in Malibu. For several years he performed there and worked with the University's Choir and other vocal groups. Marasovich also composed music for several theatre plays at the Pepperdine Theatre.

Currently Marasovich holds a position as resident organist at the Shepherd’s Grove Presbyterian Church in Irvine and Hour of Power with Bobby Schuller.

Early on, Marasovich decided to diversify, pursuing varied musical interests and different aspects of his music career. Besides being concert and church organist, Marasovich is a noted composer for film, theatre and concert stage. His work in film, documentaries and theatre performances received critical acclaim internationally. He has a long standing collaboration with the ground-breaking Bethune Theatre Danse company. His recently commissioned theatre scores include Ray Bradburry's "Frost and Fire" and "Silent Roar", a multimedia spectacle blending dance, music, video and special effects.

In 2011 Marasovich was commissioned by the LA Chapter of the AGO to write an opening composition for the Centennial Celebration Gala Concert held at the First Congregational Church. Throughout the years Zeljko Marasovich has been an active member of the AGO, serving on Executive Board of former Pasadena Chapter as well as LA Chapter. He is former Dean of the Los Angeles Chapter of the AGO.