In this study, growth parameters (i.e. condition factor, length-weight relationship, K, L∞, to), mortality rate (Z, M, and F), recruitment pattern and yield were investigated for Oncorhynchus mykiss in Karacaören I Dam Lake. Fish were collected on monthly basis between July, 2013 and June, 2014. Growth parameters were analyzed by ELEFAN with monthly length–frequency data. The b values of the length-weight relationship, mean condition factor, K (growth coefficient), L∞ (asymptotic length)and to were estimated as 3.207, 1.13, 0.33 year-1, 36.50 cm and -0.476 years, respectively. Total mortality (Z) by length-converted catch curve was estimated at 0.83 year-1, fishing mortality (F) 0.14 year-1, natural mortality (M) 0.69 year-1 and exploitation rate (E) 0.17. According to the result of Relative Yield/Recruit analysis estimated Emax>E, so in this context stock of O. mykiss was not overexploited in Karacaören I Dam Lake.