The present study was carried out to investigate the hypoglycemic effect of a polyherbal aqueousextract (Curcuma longa Linn., Emblica officinalis Gaertn., Trigonella foenum-graecum Linn.,Enicostemma littorale Blume) in alloxan-induced diabetic rats. Short term experiments showed adecrease in blood glucose levels at 2nd hr of administration of the aqueous extract in alloxan-induced diabetic rats with increase in serum insulin levels. The extract did not show any effect onblood glucose or serum insulin levels in normoglycaemic rats. Treatment with the extract (1.5gdry plant equivalent extarct/100g body weight/day) for 20 days in diabetic rats showed asignificant decrease in blood glucose and glycosylated haemoglobin levels and an increase inserum insulin levels. The aqueous extract also showed an enhanced glucose-induced insulinrelease at 11.1 mM glucose from isolated rat pancreatic islets. The extract did not show anytoxicity at the particular dose used.