One hundred and thirty splenectomies were performed at the University Hospital in Birmingham for hematologic disorders during a 12 year period. There were seven deaths of which four were related to sepsis in patients with malignant growths which probably impaired immune competence. Splenectomy was found to be uniformly satisfactory for hereditary hemolytic anemia, for hypersplenism complicating rheumatoid arthritis and for the rare instance of primary hypersplenism. Splenectomy was usually salutary in idiopathic thrombocytopenic purpura and in autoimmune hemolytic anemia. When done for diagnosis, splenectomy was definitive in about 50 per cent of the instances. Individual patients with thrombotic thrombocytopenic purpura, hairy cell leukemia and hypereosinophilia syndrome benefited. Splenectomy for hypoplastic or aplastic anemia in an attempt to increase the percentage of platelets in actual circulation offered only questionable benefit and is rarely necessary for hypersplenism secondary to portal hypertension.