Bush mango leaf (Irvingia gabonensis) is commonly used locally to treat diarrhoea. The present study evaluated the anti-diarrhoea effect of this plant extract on albino rats induced with castor oil. Fresh tender leaf of this plant was collected, air-dried, powdered and percolated in n-hexane, methanol and aqueous solvents. Diarrhoea was induced with castor oil on albino rats using standard procedures. The extract (100, 250 and 500 mg/kg) in a dose dependent manner, significantly protected the rat against diarrhoea induced experimentally with castor oil in terms of nature and number of stool droppings within 3 hrs of administration of extract, there was no significant difference when compared with the control drug (Loperamide) (P > 0.05). The study justifies the ethno pharmacological uses of this medicinal plant for treatment of diarrhoeal disease.