Abstract: This study was conducted in order to evaluate the allelopathic potential of marama bean (Tylosema esculentum (Burch) A. Schreib), a drought-avoider legume of Africa, which produces seed and tubers with potential for use as human food and animal fodder. Fresh, senesced and decaying leaves from marama were evaluated for their allelopathic potential on oat (Avena sativa) and barley (Hordeum vulgare) through in vivo studies. The studies were performed in growth chambers, using 10, 20 and 30 g of leaf tissue mixed with screened perlite as a substrate. The effects of the different leaf types were evaluated by determining root fresh and dry weight, shoot length and shoot fresh and dry weight. The results indicated the allelopathic potential of the marama leaves, being more pronounced in the fresh, moderate in the senesced and lower in the decaying leaves.