Aflatoxicosis in commercial chicken enterprise is a serious problem due to its impact on production performance. The study was envisaged to test the prophylactic efficacy of oyster mushroom, Pleurotus sajor caju, in aflatoxin fed broilers. Mushroom treatment resulted in dose dependant decrease in body weight, decrease in feed consumption and reduction in the feed conversion efficiency. Hence there is a reduction in the growth performance with reference to the level of mushroom in the feed.