Energy and protein utilization and quantitative retention of protein, fat and energy was investigated with twelve castrated West African Dwarf (WAD) sheep averaging (23.0 h 2.4 kg BW) in nitrogen and energy balance trials. Dried leaves of Leucaena leucocephala were offered as supplement at two levels 25% (diet 2) and 50% (diet 3) of dry matter intake (DM1), replacing hay in the basal hay diet. The basal hay diet without supplementation was the control. Measurements were performed by means of nitrogen and carbon balances and with the use of indirect calorimetry The digestibility and utilization of protein were influenced (P<0.05) by supplementation. Metabolisability of energy (ME/ GE) was on the average 42.9 (SEM 4.3)% being significantly (P<0.05) different among treatments. Diet 2 had a higher (P<0.05) retained protein (9.6 g/d) compared with the control diet and hence a superior (P<0.05) protein utilization than the control and diet 3, respectively. It was concluded that Leucaena leuccocephala improved protein utilization and retention in WAD sheep.