This study provided basic information on the population structure and some growth characteristics of tench (Tinca tinca L., 1758) in Lake Yeniçağa. A total 291 tench were sampled between March 2009 and July 2010. The age of sampled tench ranged from I to IX. The ratios of male and female in this population were 60.5% and 39.5%, respectively. Fork-length and weight ranged from 10.9 cm to 41.5 cm and from 24.0 g to 1127.2 g, respectively. For all individuals, von Bertalanffy growth parameters were determined as L∞ = 44.19 cm, W∞ = 1304.46 g, k = 0.236, t0 = -0342, and b = 2.999. Relation between length and weight was calculated as W = 0.015 FL2.999. Mean condition factor was calculated as 1.55 ± 0.01