The present study was undertaken to evaluate the antidiarrhoeal potential of Bryophyllum pinnatum against several experimental models of diarrhoea in Albino Wistar rats. We studied the effects of aqueous extract of the leaves of Bryophyllum pinnatum in the castor oil induced diarrhoea model. Weight and volume of intestinal content induced by castor oil were studied by the enteropooling method. The gastrointestinal transit rate was expressed as the percentage of the longest distance traversed by charcoal divided by the total length of the small intestine. Loperamide (5 mg/kg), diphenoxylate (5 mg/kg) and atropine (3 mg/kg) were used as standard drugs. Extract was used in 100, 200 and 300 mg/kg doses. At all the three doses the aqueous extract showed significant antidiarrhoeal activity against castor oil induced diarrhoea and castor oil induced enteropooling in rats. There was also significant reduction in gastrointestinal motility in the small intestinal transit test. Results obtained in this study substantiate the antidiarrheal effect of the aqueous extract of Bryophyllum pinnatum leaves and its use by traditional practitioners in the treatment of diarrhoea. Further studies are needed to completely understand its mechanism of anti-diarrhoeal action.