The effect of tail docking on growth and carcass performance was studied using 17 Turkish Tuj ram lambs born in same week. Lambs were divided into two groups with 8 animals in undocked and 9 animals in docked group. The lambs were docked using a tight rubber ring within two days after birth. The lambs in both groups were handled similarly and were 90 days suckled by their dams. After the weaning, lambs managed as one flock with the other contemporary ram lambs. All the lambs grazed in the same pasture until at the end of 6 months period and received no supplementary feeding. Lambs were slaughtered for evaluation of carcass traits. There were no differences between the treatment and control group in growth, live weight, carcass weight and dressing percentage (p>0.05). Kidney fat and mesenterial fat were higher in docked group while testicles and kidney weights were heavier in undocked lambs (p<0.05). Loin percentage in docked rams was higher then the undocked ones (p<0.05). All docked lambs survived until at the end of the 6 months experimental period. Docking in Turkish Tuj lambs did not affect growth performance and carcass leanness but some adipose tissues have been affected by the application. Lighter testicles in docked lambs might be considered as a reproductive concern, related with fat metabolism.