Thirty-six male Moghani lambs (31.4 ± 3.2 kg body weight) were used to investigate the effect of feeding heatprocessed broiler litter (HBL) on the growth performance and carcass characteristics using a completely randomized design (nine animals per diet). The used HBL was produced commercially by indirect heating (based on the flow of hot steam) BL at 80°C for 20 minutes. The experimental diets were contained HBL at the levels of 0, 70, 140 or 210 g/kg dry matter (DM). Dry matter intake (DMI), average daily gain (ADG), harvest data and carcass characteristics of the animals were recorded. The final body weight (FBW), cold carcass weight, DMI, ADG, feed efficiency (FE) and cost per unit production in the lambs fed diet free of HBL (control diet) were 51.3 kg, 27.0 kg, 1700 g/day, 245 g/day, 0.144 and US$1.83, respectively. Feeding the increasing levels of HBL had no significant effect on the FBW, DMI, ADG, FE and carcass weight. Back-fat thickness was decreased [linear (L), P = 0.05] with increasing the level of HBL in the diet. From the offal parts, weight of internal fat was decreased (L, P = 0.035) as the dietary level of HBL elevated. Dietary treatment had no effect on the weights of lean, bone and fat in carcass and dissected legs. Fat weight of dissected loin was decreased (L, P = 0.05) as the dietary level of HBL increased. As the level of HBL elevated in diet, cost per unit production was decreased (L, P = 0.04). It is concluded that using HBL up to 210 g/kg DM in diet of fattening Moghani lambs was possible without any effect on feed intake, growth performance and animal health, but reduced loin fat, internal fat and cost per unit production.