Aqueous, ethanolic and hexane fractions of Momordica cymbalaria fruits were prepared and given individually at different doses to different batches of rats (both normal and alloxan diabetic rats) after an overnight fast. The blood glucose levels were measured at 0, 1, 3, 5 and 7 h after the treatment. The aqueous extract of Momordica cymbalaria at a dosage of 0.5 g/kg b.w. is showing maximal blood glucose lowering effect in diabetic rats. The same dosage did not produce any hypoglycemic activity in normal rats. The antihyperglycemic activity of Momordica cymbalaria fruit was compared with the treatment of Glibenclamide, an oral hypoglycemic agent.