Željko Kertez, Tuba, was born in Koprivnica, Croatia. After he finished elementary school in Koprivnica, he enrolled in Varaždin Music School in the class of prof. Stjepan Rukljić. During his education he won the first prize at the 38th National competition of students of music and dance in Rijeka. Soon afterwards he passed the audition for the Orchestra of the Middle European Initiative, where he played for two seasons. After he graduated in the Music school in Varaždin, he enrolled in the class of prof. Šime Vulelija and Danijel Rajković at the Music academy of the University of Zagreb where he graduated in 2005.
In 2005 he won the audition for the Mediterranean Youth Orchestra, where he played for one season. He has attended master classes with the eminent world soloists such as Jens Bjorn Larssen, Henrik Jan Rennes, Ben van Dijk, Mel Culbertson, Walter Hilgers and others. He is also active as a pedagogue and he was invited to teach at most important student music camp in Slovenia – UPOL OrkesterkamP.
Željko holds the position of Solo tuba at the Croatian National Theatre in Zagreb since 2005. He is also active as a soloist and he appeared with the Tokai Sagami Wind Orchestra in Yokohama in 2013, where he performed the Artiunian Tuba Concerto with great success. He is engaged as conductor of the Kutina Municipal Brass Orchestra - Kresimir. He is also active as a chamber musician in the Busina Brass Quintet.
Since 2014, Željko is an International Artist in Residence with the English Brass Academy.
Željko is the Vice-president of the Croatian Association of Trombone and Tuba players – Busina and the Artistic Co-director of the Šibenik Summer Brass Academy