This study was carried out to investigate the fattening and carcass characteristics of German Blackheaded Mutton (GBM) x Awassi (A) F1, Hampshire Down (HD) x A (F1) and HD x (HD x A) B1 male lambs. Nine GBM x A (F1), eight (HD) x A (F1) and eight HD x (HD x A) B1 male lambs were used for fattening traits, and six of each breed for carcass traits. The lambs were fed, from the beginning at approximately 20 kg of live weights to the finish at 45 kg, alfalfa hay 100 g/head/day and concentrates ad libitum. For statistical analysis, one way analysis of variance was used. For GBM x A (F1), HD x A (F1) and HD x (HD x A) B1 lambs, daily gains and feed gain ratios were 351.18 g and 3.77 kg, 367.98 g and 3.95 kg, 357.94 g and 3.67 kg respectively. All carcasses were divided into five cuts namely leg, shoulder, back, loin and others. To obtain knowledge about carcass composition, leg and shoulder cuts were dissected. Dressing percentages were found to be 48.54, 50.99 and 50.97 % (P<0.01); the ratios of leg weights in the carcass were 33.09, 33.41 and 32.26 %; shoulder weights 17.72, 17.68 and 17.72 %; back weights 9.29, 9.13 and 9.56 %; loin weights 8.17, 8.23 and 8.83 %; the other weights 25.43, 26.09 and 26.80 %; kidney knob and channel fat weights 1.17, 1.60 and 1.70 %; eye muscle areas were 13.08, 14.75 and 14.42 cm 2 , back fat thicknesses were 9.06, 9.04 and 9.42 mm. The ratios of lean meat weights in the leg cut were 56.84, 59.94 and 59.86 % (p<0.01), fat weights 26.50, 24.55 and 23.86 %, bone weights 16.66, 15.51 and 16.27 %. The ratios of lean meat weights in the shoulder cut were 57.97, 57.45 and 57.27 %, fat weights 22.51, 25.73 and 25.68 %, bone weights 19.51, 16.82 and 17.05 % for breeds in the above order.