We present a phylogenetic analysis of snow voles by combining all published cytochrome b sequences of 47 species of Microtus, Blanfordimys, Neodon and Chionomys and a new sequence from Chionomys gud. By applying powerful, modern approaches to phylogenetic reconstruction such as maximum likelihood (ML) and Bayesian inference methods (BI), we provide new information on the relationships between Chionomys and Microtus. Both phylogenetic analysis methods showed that the genus Microtus is paraphyletic with respect to Blanfordimys, Neodon and Microtus gregalis. The BI topology recovered strong support for the monophyly of Chionomys + Microtus gregalis, while th monophyly of Chionomys was supported only by the ML analysis. The two Chionomys lineages (defined by molar morphology and karyological features), “nivalis” (C. nivalis) and “roberti” (C. gud and C. roberti), were strongly supported by cytochrome b analysis.