1. A trial was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) concentration on performance parameters, carcase composition, thiobarbituric acid reactive substances (TBARS) and fatty acid composition in leg and breast muscle and serum lipoprotein concentrations. 2. A total of 128 male chickens were allocated to 4 dietary treatments (0, 1, 2 and 3% CLA) and given a standard starter diet from d 1 to d 21 and a finisher diet from d 22 to d 42. Breast and leg muscles were stored at 4 degrees C for 1, 3 or 7 d. Fatty acid composition, TBARS and pH were determined in muscles. 3. Weight gain and feed conversion ratio were positively influenced by dietary CLA level. CLA isomer concentration in muscles increased linearly (P < 0.01) as dietary CLA increased. Addition of CLA to feeds significantly increased saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) and decreased (P < 0.01) monounsaturated fatty acid (MUFA) in leg and breast tissues. 4. Muscle pH decreased with duration of refrigerated storage. TBARS values were significantly (P < 0.01) influenced by dietary CLA and storage time. CLA increased total cholesterol, LDL-cholesterol and HDL-cholesterol, but reduced triglycerides in the plasma of broilers.