The Social Vole Microtus socialis differs from non-socialis voles from Iran by its smaller size and relatively broader inter-orbital region. Discriminant Function Analysis based on 14 cranial measurements classified all Iranian specimens into their actual group (i.e. socialis or non-socialis). A dotted distribution map of M. socialis is provided for Turkey, Syria, Lebanon, Iraq and Iran. Isolated records from Khorassan and Fars, both in Iran, are discussed. Inter-locality variations were significant in dimensions of the tooth-row, diastema, rostrum, bullae and braincase breadth. The postero-internal loop of the second upper molar was either absent or rare; only in voles from Lebanon and Syria was the incidence of this morphotype observed in about one-third of the specimens. Marginal populations seemed to be morphologically most distant.