Background: Diabetes mellitus is a multifactorial metabolic disorder with several microvascular and macrovascular complications. Several plants have been used as dietary adjuvants to conventional drug therapy. Garcinia indica exhibits significant hypolipidemic and hypoglycemic activity. This study was conducted to evaluate the hypoglycemic effects of methanolic extract of seeds of Garcinia indica on blood glucose levels in Streptozotocin induced diabetic albino rats.Methods: Five groups of wistar albino rats (n=6) weighing 150-200g of either sex aged 3-4 months were obtained for the study. After overnight fasting, streptozotocin (50mg/kg) was administered intraperitoneally to induce diabetes. Five groups are: Group-1: Non diabetic control group, Group-2: diabetic control, Group-3: diabetic standard, Group-4: test group, Group-5: half of test + half of standard. Fasting blood sugar was estimated on 1, 3, 7, 14 and 28th day by capillary blood glucose method. The data obtained were subjected to statistical analysis.Results: In this study, following Streptozotocin administration the blood glucose levels increased in all groups on day 0. In group 2, blood glucose level gradually increased to 445.6±1.75mg/dl over a period of 4 weeks. Following glibenclamide administration in Group 3 - there was a gradual reduction in blood glucose levels: 269.8mg/dl - day 7 to 101.8mg/dl - week 4. Group 4 - persistent and significant (p<0.05) fall in blood glucose levels reaching upto 107mg/dl at the end of 4 weeks. Group 5 - 330mg/dl on day 1 which significantly (p<0.05) reduced to 101mg/dl on day 28. There was improvement in weight in group 4 and group 5 diabetic rats.Conclusions: The extract alone and in combination with glibenclamide showed significant hypoglycemic activity in comparison to diabetic control group.