Alcoholic extract of whole fruit of Momordica charantia was prepared. Adult healthy albino rats were divided into four groups and received a dose of 6 mg/l00 gm. body weight of alloxan monohydrate. Animals of group I served as diabetic control group. The animals of II, III, and IV groups received 25 mg, 50 mg and 75 mg doses of the extract respectively for different durations. 75 mg dose showed increase in body weight. All doses of alcoholic extract of M. charantia were able to decrease the blood sugar level significantly. Extract feeding showed definite improvement in the islets of Langerhans. No toxic effect was observed in the liver The significant features of the study have been blood glucose once lowered by the treatment with M. charantia fruit extract remained static even after discontinuation of drug for 15 days. Blood sugar never fell below normal values even with a high dose, in pancreatic islets, beta cells showed definite improvement.