Embelia ribes (common name, Vidanga) is extensively used in traditional system of medicine for treatment of various disorders. It is described in Ayurveda, as a powerful anthelmintic, antifertility and antihyperlipidemic agent. The present study was undertaken to investigate modulatory effect of 6 weeks' chronic oral administration of E. ribes ethanolic extract on diabetes mellitus induced by a diabetogen, streptozotocin (STZ) with special reference to changes in glucose levels, glycated haemoglobin status and cardiac toxicity. STZ treatment (40 mg/kg iv) resulted in significant increase in blood glucose levels, glycated haemoglobin levels, heart rate (HR) and systolic blood pressure (SBP). Oral administration of E. ribes ethanolic extract in dose of 100 mg/kg and 200 mg/kg significantly reduced the levels of blood glucose, glycated haemoglobin, heart rate (HR) and systolic blood pressure (SBP) in animals when compared with diabetic rats.