Ten patients with thrombotic thrombocytopenic purpura (TTP) were studied retrospectively. The male:female ratio was 2:3 and the median age was 27 years. Six patients are alive one-half to 18 years after the onset of the disease. Four of these patients underwent emergency splenectomy and received antiplatelet drugs. Of the remaining two, one responded to splenectomy and the other had received a short course of aspirin therapy. The study supports the usefulness of splenectomy and/or antiplatelet agents in the treatment of TTP.