Abstract: Piper longum (Piperaceae family) is used in Indian traditional medicine as a remedy for various disorders including diabetes mellitus. The aim of the present study was to investigate the antihyperglycemic and antilipidperoxidative effects of ethanolic extract of Piper longum dried fruits (PLEFet) in alloxan induced diabetic rats. Diabetes mellitus was induced in overnight fasted (12 h) Wistar rats by single intraperitoneal injection of freshly prepared solution of alloxan monohydrate (150 mg kg-1 bw) in physiological saline. The blood glucose level, carbohydrate metabolizing enzymes and the status of lipid peroxidation and antioxidants were assayed using specific colorimetric methods. Oral administration of PLEFet has shown significant antihyperglycemic, antilipidperoxidative and antioxidant effects in diabetic rats. PLEFet also corrected the metabolic alterations observed by the activities of several carbohydrate metabolizing enzymes (hexokinase, glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, fructose 1.6-bisphosphatase and glycogen phosphorylase) in alloxan induced diabetic rats. The antihyperglycemic effect of PLEFet is comparable to that of the standard reference drug, glibenclamide. Present results indicate that PLEFet has potent antihyperglycemic and antilipidperoxidative effects in alloxan induced diabetic rats. PLEFet can therefore be used as an alternative remedy for diabetes and oxidative stress associated diabetic complications.