In November 1951 he ordained deacon and then priest in the appointment of the Transfiguration Cathedral in Leningrad.
On 26 June 1962 he was tonsured a monk with the name Seraphim in the Pskov-Caves Monastery, on July 1 of the same year elevated to the rank of Archimandrite.
e was a member of the Synod Commission for the preparation of the Local Council of the Russian Orthodox Church in 1971.
On 25 June 1971 Archbishop of Kursk and Belgorod appointed Metropolitan Seraphim Krutitsy and Kolomna, a permanent member of the Holy Synod.
He died during the night of 22 April 1979, the feast of Easter in the Holy Transfiguration Cathedral in Leningrad (near which he lived and which used to come to pray in the last years of his life) during the Divine Liturgy.