Vagharshak Kotoyan was born in Tbilisi, Georgia. From 1944 to 1946, he studied composition at Tbilisi conservatory. In 1950 he graduated from the Department of Composition at Yerevan State Conservatory (named after Komitas). From 1950 to 1953, he continued his studies at Armenian Culture Home in Moscow. From 1965 to 1967, Kotoyan was the director of the Alexander Spendiaryan House-Museum, and in 1968 he headed the Music Department of the Ministry of Culture of Armenia. From 1969 he headed the State Philharmonic Society of Armenia. In 1963 he was awarded the title of Honored Artist of Armenia. Kotoyan died in Yerevan.