Abstract: The hypoglycemic effects of aqueous and methanolic leaf extract of Vitex doniana were evaluated in normal and alloxan-induced diabetic rats using standard analytical protocols. The potency of the leaf extract was compared with that of oral anti-diabetic agent (Glibenclamide). A total of 35 albino rats divided into seven groups of five rats each comprising one normal untreated group as animal control, one diabetic untreated group as diabetic control, one normal treated with 750 mg kg-1 b.wt. as reference group, three diabetic groups treated with 250, 500 and 750 mg kg-1 body weight respectively and one diabetic group treated with 5 mg kg-1 Glibenclamide as standard. The result of acute toxicity test obtained indicated lethal dose (LD50) of greater than 5000 mg kg-1 extract. Results indicated that administered doses of 250, 500 and 750 mg kg-1 body weight of the leaf extract showed significant (p<0.05) reduction of blood glucose level, renal function markers (serum creatinine, urea and uric acid) and serum electrolytes (Potassium and sodium ions) in a dose dependent manner in reference and diabetic groups when compared to normal and diabetic control groups, respectively. The results also indicated that administration of the extracts caused a significant (p<0.05) increased in the serum total proteins and albumin levels and a significant (p<0.05) decrease in the total bilirubin levels in the diabetic rats. These results imply that the leaf extract is relatively safe and could be used in the management of diabetes mellitus and associated complications.