This study was aimed at assessing the antidiabetic and hepatoprotective effects of combined aqueous leaf extract of Azadirachta indica and Mangifera indica in alloxan monohydrate-induced diabetic Wistar rats. Fresh leaves extract of Azadirachta indica and Mangifera indica were prepared using distilled water in appropriate stock concentrations and used in a 14-day treatment. Acute toxicity studies of the combined extract conducted in rats showed no toxicity up to 5000mg/kg. Experimental animals were acclimatized for 14 days while diabetes was induced using alloxan monohydrate (150mg/kg) intraperitoneally. After 14 days of treatment of diabetic rats with 300mg/kg, 500mg/kg 700mg/kg respectively as well as with 150mg/kg metformin, there was increase in weight, the blood glucose levels decreased significantly (p<0.05) whenc compared to untreated diabetic rats (diabetic control). Also, there was a significant p<0.05) reduction in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels of rats treated with different doses of the extract compared to the diabetic control. A dose dependent antidiabetic and hepatoprotecitve effect was observed and the combined extract had a close similar effect as the standard drug metformin. Therefore, combined aqueous leaf extract of Azadirachta indica and Mangifera indica exhibit antidiabetic and hepatoprotective and this is due to the presence of phytochemical constituents in the leaf part of the plants.