Darevskia rudis (BEDRIAGA, 1886) occupies a wide range of altitudes in the Black Sea region of Turkey. A total of 62 individuals of this lizard from three populations/locations at different altitudes (Province of Artvin: Ardanuc, 2137 m a.s.l., Borcka, 1277 m a.s.I., Cermik, 700 m a.s.I.) were studied for body size and age using skeletochronology. In both sexes, mean body size and age were smaller/lower in the highest altitude population than in the lower altitude populations. A significant positive correlation was found between age and snout-vent length in the females of the high altitude populations, however, not for Cermik females and the males of all three populations. Sexual size dimorphism was male-biased in the lowest (Cermik) population, but female-biased in the higher altitude (Borcka and Ardanuc) populations. The skeletochronological analyses revealed distinct differences in body size and age structure between low and high altitude populations of D. rudis.