Abstract The toxic effects of cowpea and limabean extracts containing hemagglutinins and pathological changes in organs of weanling and growing rats were investigated. Livers of weanling rats injected with limabean hemagglutinin mean lethal dose (MLD), showed marked congestion of the sinusoids. Livers of growing rats thus inoculated, including those given the lethal and sublethal doses of cowpea hemagglutinin, did not show any marked lesions. There was evidence of marked congestion of the medullary sinusoids in the spleen and of the glomeruli in the kidney of weanling and growing rats inoculated with either the sublethal doses of limabean hemagglutinin or lethal doses of cowpea and limabean hemagglutinins. Slight hemorrhages were observed in the intestinal walls of weanling rats while slight thickening of the alveolar septa took place in the lungs of rats dosed with the lethal and sublethal doses of cowpea hemag-glutinin. The testis, brain and heart of weanling and growing rats were unaffected by hemagglutinin treatment.