Diabetes mellitus (DM) is a metabolic disorder, characterized by absolute or relative deficiency in insulin secretion or insulin action. The synthetic oral hypoglycemic drugs used in clinical practice have significant unwanted effects. Plant based drugs are considered to be less toxic and free from adverse effects in comparison to modern allopathic drugs. Pongamia pinnata (L.), locally known as Karanja, is a mangrove plant belonging to the family, Fabaceae. The present work aimed to evaluate the antioxidant and antidiabetic potency of standardized ethanolic extract of Pongamia pinnata (EP) to flavonoids on alloxan-induced animals and its effect were compared with reference glibenclamide (GL). Inbreed adult male Charles-Foster (CF) albino rats were used in the experiment for hypoglycemic activity in oral glucose tolerance test (OGTT) and normoglycemic rats, and antidiabetic activity in alloxan induced rats. Preliminary phytochemical screening revealed that EP showed positive response to alkaloids, saponins and triterpenes, tannins, flavonoids, carbohydrates and sterols. Further, the flavoniod content of EP was found to be 28.1±0.7 mg in quercetin equivalent/ 1g extract. Results revealed in the present experiment that the routine post-treatment for 21 days with the EP showed potential hypoglycemic activity in OGTT and normoglycemic rats and antidiabetic activity in alloxanized rats. In conclusion, isolation and establishment of exact mechanism of action of specific compound from EP is to be carried out in the future.