Skeletal muscle atrophy is one of the serious and less studied diabetic complications.Leucine is an essential amino acid that is transported into most mammalian cells by System L. The current study was conducted to assess the effect of leucine on diabetic skeletal muscles. Forty male Wister rats were allocated into four groups; control, Leucine-treated group was subjected to daily oral supplement of Leucine (1.35 g/kg) for 8 weeks, STZ-diabetic group was treated with single intravenous injection of STZ (45 mg/kg) and STZ-diabetic group supplemented with leucine (1.35 g/kg) for 8 weeks. Body weight and histopathological analysis of soleus muscle were evaluated. There was a significant increase in body weight of leucine group at p> 0.05. Leucine supplementation attenuated loss of soleus muscle mass observed in STZ diabetic rats. These findings may suggest protective effect of leucine against diabetic muscle loss. Leucine supplementation attenuated loss of soleus muscle mass observed in STZ diabetic rats. These findings may suggest protective effect of leucine against diabetic muscle loss.