The composer, music theorist and publicist Cestmir Gregor was born into a family of musicians, his father was a well-known music teacher and promoter. After the end of the Second World War he entered the Conservatory of Music in Brno (from September 1945, studied composition with Jaroslav Kvapil). After the interruption of study as a result of heavy illness he continued his studies with Jaroslav Kvapil at the Janáček Academy of Perfoming Arts (1950-54). In the years 1945-47 he studied also music science at Brno University.
In practice he began as a freelance composer (until August 1968 he belonged to the Czech most performed composers of orchestral music). As a music critic and journalist he was active since 1946. Having moved from Brno to the Ostrava region in the mid-fifties he was briefly the secretary of the local organization of the Union of Czechoslovak Composers (1958-59) and from October 1959, he joined the Czechoslovak radio in Ostrava as the head of its music broadcasting. In the years 1965-1970 he studied JAMU again, this time as a regular listener and received the diploma. In 1972 he was dismissed from his job in the radio following the then communist purges and there was issued a ban on publishing or performing his works in public (valid for one year). In 1976 he moved to Prague where became a resident and had been earning his living as a composer, music theorist and publicist.