Abstract: In this study, the ages of Capoeta capoeta umbla inhabiting in Hazar Lake (Turkey) were determined from otolith. The lengths of fish at previous ages were estimated from otolith length by using back-calculation method. The calculated fork length values for male, female and all fish samples ranged 67.26-329.27, 71.05-341.03 and 69.36-336.33 respectively. In all age groups, calculated lengths were always found smaller than measured lengths. The relationship in calculated lengths was significantly different between some age groups, but did not differ between females and males It was found that the gap between calculated length and measured length was gradually close to each other with increasing fish age.