Aegle marmelos is a medium sized tree, widely distributed in Asia and Africa. The plant is widely used in the ayurvedic system of medicine. Traditionally the plant has been used for the treatment of various ailments such as pain, fever, inflammation, respiratory disorders, dysentery and diarrhoea. To justify its folklore, present study was undertaken to investigate the antidiarrhoeal activity of the ethenolic extract from the fruit of Aegle marmelos. Preliminary phytochemical screening, acute toxicity study and antidiarrhoeal activity were studied on castor oil induced diarrhoea at 400 mg and 800 mg/kg body weight. The preliminary phytochemical screening of the extract revealed presence of alkaloids, protein, tannins, sterols, phenolic compounds and saponins. Acute toxicity study revealed no visible signs of toxicity in mice even at the highest dose of 2000 mg/kg body weight. The doses of ethenolic extract of A. marmelos significantly decreased (P<0.05) the total number of diarrhoeal faeces in mice. Percentage of inhibition of diarrhoeal faeces at 800mg/kg was comparable with standard drug Loperamide. The study concluded that Aegle marmelos fruit extract has the antidiarrhoeal activity in castor oil induced diarrhoea in mice.