Born in the city of Juybar, Iran. Mortazavi studied music in Tehran. He was trained in improvisation, orchestration, arrangement, quarter tone technique, and dastgah by various well-known violinists in Iran. Mortazavi started learning the violin under the supervision of Masoud Namazian when he was three years old. In a Nowruz 1991 interview with Alireza Amirghassemi on The Tapesh Show, Mortazavi claimed that as part of his tutelage, Namazian had him focus for the first three months only on music theory to learn the notes and scales and then apply them to the violin, as Mortazavi did not attend music school, and advised his parents to not let him touch the violin during that time. Mortazavi claimed his mother hid his violin in a cupboard for that period, although he would often play on the violin in secret until his mother eventually caught him. He would later take lessons from Ali Tajvidi, Parviz Yahaghi, Habibollah Badiei, Jahangir Kamiyan, Hasan Shamaizadeh.