Body size and age structure of a highland population of Hyla orientalis BEDRIAGA, 1890 (77 = 41) from Kantarh, located at about 800 m a.s.l. in the Black Sea Region of Turkey, was studied using skeletochronology. The maximum observed longevity was eight years in females and seven in males. Age at maturity in this population was three years in females and two in males. There was a significant difference in age between males and females (Independent Sample t test, p < 0.05, t = -2.455). A significant positive correlation was found between age and snout-vent-length both in males and females. To demonstrate the role of altitude on age structure and body size of the Kantarh population, the potential effects of the parameters 'duration of activity period' and 'altitude' were analyzed by comparing present data with data available from the literature.