This study was carried out to determine the fattening performance, body measurements, and slaughter and carcass characteristics of Akkaraman lambs fattened under indoor and outdoor housing systems. Fourteen Akkaraman lambs were used for the current study. Lambs were less than 3 months of age having about 20 kg live weight, and fed concentrated feed ad libitum together with 150 g of dehydrated alfalfa per day for 8 weeks. The daily live weight gain of Akkaraman sheep in the indoor housing system was 313 g while this value was 277 g a day in the outdoor housing system (P<0.05). Also, the average total feed intakes (kg) and the feed conversion ratios of Akkaraman lambs in indoor and outdoor shelters were found to be 148.81 kg and 146.95 kg, and 4.10 and 4.49 (P>0.05), respectively. The differences between the housing systems in terms of total chest depth increase, chest depth and total body length increase were statistically significant (P<0.05). Moreover, the differences in dressing percentage (P<0.01), heart+lungs+liver weight (P<0.05), fore-ribs weight and proportion (P<0.05) from slaughter and carcass characteristics were statistically significant. Also, the pH, hardness and color values as L*, a*, b*, H* and C* at 24 h after slaughter were determined.