In 1975 Sergey Koshonin entered the Leningrad State Institute of Theatre, Music and Cinematography in the class of A.I. Katsman and L. Dodin. After graduating from the school, he served for 20 years at the Molodezhny Theatre on the Fontanka in Saint Petersburg. At the Molodezhny Theatre on the Fontanka under the direction of Semyon Spivak he played more than a hundred roles and worked with director Vladimir Malyshchitsky.

He performed his most significant roles in legendary productions based on works by Alexander Volodin. In 1995 he began working in television production. The first project was the Romani band "Cabriolet". Then came the creation of and work in an entreprise in the creative association "Art-Piter". Honored Artist of Russia (2006).