Diospyros peregrina Gurke. (Ebenaceae) is a small middle sized tree grows luxuriantly in the plainsof costal West Bengal, India. The objective of the study was to explore the antidiabetic activity ofmethanol extract of matured fruits of Diospyros peregrina to substantiate the folklore claim oftraditional practitioners. It was also aimed to establish correlation with reduction of oxidativestate associated with diabetes. Methanol extract of matured fruits of Diospyros peregrina wasadministered orally at doses of 150 and 300 mg/kg body weight for 12 consecutive days tonormal and streptozotocin induced diabetic rats. Fasting blood glucose level was estimated inboth normal and diabetic rats while serum lipid profiles, liver glycogen level and pancreaticthiobarbituric acid reactive substances (TBARS) were evaluated for diabetic rats. Initial and finalchanges in body weight were also recorded. Oral glucose tolerance test was performed during thecourse of study. Experimental findings showed significant antidiabetic potential of extract in termof reduction of fasting blood glucose level of both normal and diabetic rats. It was found thatextract at the dose of 300 mg/kg body weight is more effective and percentage reduction (55.64)of elevated blood glucose level is comparable to that of standard drug glibenclamide (60.60) at adose of 10 mg/kg body weight. Observed data found statistically significant in reduction ofserum lipid and pancreatic TBARS levels whilst improvement was observed in liver glycogenlevel and body weight profiles in extract treated diabetic rats.