The antidiabetic effect of aqueous and hexane extracts of Swertia chirata was studied in streptozotocininduced diabetic rats. Type II diabetes was induced by injecting streptozotocin (STZ) subcutaneously to adult (ten to twelve weeks old) mixed albino male (Long Evan's Strain) rats. Aqueous extracts of Swertia chirata at 75 and 125 mg/kg body wt. (AqSC75 and AqSC125), hexane extracts of Swertia chirata at 50 and 109 mg/kg body weight (HeSC50 and HeSC100) and glibenclamide at 600 pg/kg body wt. (an oral antidiabetic drug) were given orally for 16 days to STZ induced diabetic rats. In diabetic rats, all the different extracts as well as glibenclamide produced a significant (P<0.01) antihyperglycemic effect, the markedly higher being in the groups treated with HeSC50 and HeSCioo followed by AqSC125 and AqSC75. Both aqueous and hexane extracts of Swertia chirata exhibited anti-hypercholesterolernic effect in STZ diabetic rats. But glibenclamide had virtually no cholesterol lowering effect. All forms of extracts at different doses decreased serum TAG levels significantly (P<0.01) in diabetic rats; the highest decrease (60%) in TAG level was observed in animals of the group treated with HeSCioo. In STZ-rats, a fall in SGPT levels was observed in all the groups treated with different extracts and glibenclamide; the Most affected was the group treated with HeSC5o. On the other hand, an increase in SGOT level, another liver enzyme, was observed in groups treated with glibenclamide. But aqueous and hexane extracts of Swertia chirata decreased SGOT levels compared with diabetic control group. Thus the above observations suggest that extracts, from Swertia chirata possess antidiabetic principle and can presumably be used for the treatment of diabetes mellitus.