The antidiabetic effect of seeds of Strychnos potatorum Linn. was evaluated in a model of diabetes mellitus using streptozotocin (40 mg/kg bw, ip). Changes in fasting blood sugar were estimated periodically for 12 weeks along with weekly measurement of body weight, food and water intake for 4 weeks. The antidiabetic effects were compared with glipizide as the reference hypoglycemic drug. Strychnos potatorum Linn.(100 mg/kg po) significantly reduced fasting blood sugar, the effects being comparable with glipizide (40 mg/kg, po), an established hypoglycemic drug. It also increased body weight along with decreased food and water intake in streptozotocin-induced diabetic rats. Taken together, Strychnos potatorum Linn. shows promise as an effective hypoglycemic compound worthy of future pharmacological investigations.