Before 2008, HIV-1 subtype A was the predominant genetic variant in the Novosibirsk oblast of Russia as well as in most parts of this country. However, a rapid spread of the recombinant HIV-1 02_AG form has been reported in Novosibirsk since 2009. We have analyzed the genome of the 10.RU.6637 isolate, a HIV-1 02_AG recombinant form, which represents a monophyletic cluster of the HIV-1 variants widespread in this region. Phylogenetic analysis has shown that the Siberian 10.RU.6637 isolate displays the highest sequence identity to the HIV-1 subtype AG forms circulating in Uzbekistan. However, recombination analysis of 10.RU.6637 has demonstrated that this isolate is a recombinant form between HIV-1 subtype A and CRF02_AG, differing in its genetic structure from both the CRF02_AG reference sequences and the Central Asian variants of HIV-1 02_AG.