The present investigation was undertaken to study the effects of chronic oral ramipril (1 mg/kg) treatment in streptozotocin (STZ) induced diabetic rats. Single tail vein injection of STZ (45 mg/kg, i.v.) produced a diabetic state exhibiting all the cardinal symptoms such as loss of body weight, polydipsia, polyuria, glucosuria, polyphagia, hypoinsulinaemia and hyperglycaemia. The diabetic state was also found to be associated with bradycardia, hypothyroidism, cardiac depression and cardiomyopathy. Ramipril treatment prevented STZ-induced hypertension, bradycardia, hypothyroidism, hyperchosesterolaemia and partially the cardiomayopathy. Ramipril treatment could not, however prevent STZ-induced loss of body weight, polyuria, polydipsia, polyphagia, hyperglycaemia, hypoinsulinaemia, hypertriglyceridaemia and cardiac depression. Our data suggests that ramipril has a few beneficial effects in the STZ-treated diabetic rats.