Pure red cell aplasia is uncommon disorder characterized by finding of anemia, absence of nucleated red blood cell in the marrow, absence of reticulocytes in the peripheral blood and normal peripheral platelet and leukocytes counts. We experienced one case of pure red cell aplasia associated with hemolytic anemia characterized by hemoglobinuria, reticulocytopenia, and erythroid hypoplasia of the bone marrow. The cause of the illness was not definitely identified, but we concluded that this patient had simultaneous occurence of PRCA and hemolytic anemia following administration of diphenylhydan. toin after craniotomy rather than virus or bacteria induced. The simultaneous occurance of PRCA and hemolytic anemia is uncommon and the mechanism for diphenylhydantoin induced PRCA and hemolytic anemia is unclear.