The purpose of this study were to determine effects of fattening systems on fattening performance (n=39) and slaughter and carcass characteristics (n=24) in male Tuj lambs. Three different fattening groups were formed as extensive (n=13), semi-intensive (n= 13) and intensive (n=13). Lambs in the extensive group were grazed in pasture. In addition to pasture, concentrated feed was given to lambs in the semi-intensive group. High quality fodder and concentrated feed were given to those in the intensive group. The study was completed in 90 d. Final live weights of extensive, semi-intensive and intensive groups were 31.19, 41.22, and 40.56 kg (P<0.001), respectively, and for daily live weight gain were (DLWG) 117.52, 229.66, and 221.11 g (P<0.001), respectively. Feed conversion rates (FCR) were 3.05 and 5.16 respectively in the semi-intensive and intensive fattening. It was found that hot carcass weight was 13.41, 19.51, and 19.89 kg (P<0.001) in extensive, semi-intensive, and intensive fattening groups respectively. Hot carcass yield was 43.11, 46.95, and 49.77% (P<0.001) in extensive, semi-intensive, and intensive fattening groups respectively. Consequently; leg, foreleg, shoulder, neck, flank, and kidney percentages, and spleen and full stomach weights of lambs in the extensive group were higher than in semi-extensive and entensive groups. Although there was no statistical difference between semi-extensive and entensive groups in respect to fattening performance, slaugher weight, hot and cold carcass weights, entensive group was higher than the other groups in respect to hot and cold carcass yield.