Anti-diabetic effect was observed with Cocculus hirsutus when given as an aerial part extract in normal as well as diabetic rats. The effect, however, was more pronounced in diabetic animals in which administration for 15 days after streptozotocin (STZ)-induced diabetes, significantly reduced blood glucose levels. After STZ-induced diabetes, it was observed that both standard drug (glibenclamide) and methanolic extract of C. hirsutus were significantly superior to control in reducing blood sugar on long treatment (15 days). The data suggested that C. hirsutus could be of benefit in diabetes mellitus in controlling blood sugar. The present investigation established pharmacological evidence to support the folklore claim that it is an anti-diabetic. © 2007 Academic Journals. © 2009 Elsevier B.V., All rights reserved.