Vadim Petrov is the son of a Russian emigrant doctor MUDr. Vadim V. Petrov, a descendant of the ancient noble family Repnin-Rěpninský with a family tradition since 842. Grandfather Vasily A. Petrov (1872 - 1949) lived in Prague, was an important figure of Russian social life, associated with the Orthodox Church of St. Cyril and Methodius in Resslov Street, a close friend of Bishop Gorazd and Chaplain Vladimir Petrek, shot by the Nazis.

Mother Adéla, b. in Turnov, was a soloist of the Singing Association of Prague Teachers, the oldest women's choir in Bohemia, zal. 1912. Influenced by church and choral works, he composed "Biblical Songs" for his mother at an early age, and after their performance in the Church of the Virgin Mary in Stará Boleslav, Master Josef Bohuslav Foerster, an important composer, personally congratulated him.