Cassia auriculata L (CFEt). (Ceasalpiniaceae) has been used traditionally as antidiabetic and has been proven scientifically to possess high antioxidant activity and anticancer properties. In experimental diabetes, enzymes of glucose and fatty acid metabolism are markedly altered. Persistent hyperglycaemia is a major contributor to such metabolic alterations, which lead to the pathogenesis of diabetic complications. Fatty acids influence translocation of glucose transporters and insulin receptor binding and signalling, in addition to cell membrane fluidity and permeability. It is thus suggested that fatty acids may have an essential role in the development of insulin receptor and diabetes. Specific combinations of fatty acids within phospholipids and triglycerides were indicated to exhibit the strongest associations with the risk of diabetes. The aim of this study was to evaluate the effect of CFEt on blood glucose, plasma insulin and fatty acid composition of total lipids in liver, kidney and brain of control and streptozotocin diabetic rats. The analysis of fatty acids showed that there was a significant increase in the concentrations of palmitic acid (16:1), stearic acid (18:0) and oleic acid (18:1) acid in liver, kidney and brain, whereas the concentrations of linolenic acid (18:3) and arachidonic acid (20:4) were significantly decreased. Oral administration of CFEt at 0.45 mg/kg body weight to diabetic rats decreased the concentrations of fatty acids, viz., palmitic, stearic, and oleic acid whereas linolenic and arachidonic acid were elevated. These biochemical observations were supplemented by histopathological examination of liver and kidney section.These results suggest that CFEt exhibits antidiabetic and antihyperlipidemic effects in STZ induced diabetic rats. It also prevents the fatty acid changes produced during diabetes.