The role of oxidative stress in the development of diabetes mellitus and its vascular complications are extensively studied. Hyperglycaemia causes oxidative damage by generation of reactive oxygen species and results in the development of complications. The present study was undertaken with the objective of exploring the anti-hyperglycaemic potential of phenolic compounds enriched semipurified extract of Bauhinia purpurea bark in streptozotocin induced (STZ) diabetic rats for four weeks and to study oxidative stress and antioxidant status. Rats were rendered diabetic by single injection of streptozotocin (60 mg/kg body wt, ip). At the end of the treatment period, the level of blood glucose, serum biochemical markers, serum cholesterol levels and liver malondialdehyde, tissue antioxidant levels were measured. A marked rise was observed in the levels of fasting blood glucose, cholesterol, lipid peroxidative products and a significant decrease in tissue antioxidants (reduced glutathione) levels in STZ treated rats. Oral administration of two semi purified extracts B1 and B2 (100 and 50 mg/kg body wt each, p.o) decreased fasting blood glucose levels of STZ-treated diabetic rats significantly (P < 0.01), when compared with control rats. In addition, the extracts showed favorable effect (P < 0.01) on the reduced tissues antioxidants level, liver glycogen level, cholesterol level, with significant (P < 0.01) reduction of elevated lipid peroxidation products. Our study showed the antioxidant effect of phenolic compounds enriched semipurified extracts of B. purpurea in STZ induced experimental diabetes. The results also suggested that this polyphenolics rich extract could be potentially useful for hyperglycaemia treatment to correct the diabetic state.