Thirteen patients with thrombotic thrombocytopenic purpura were treated at our facility between 1985 and 1991. All patients were treated with plasma therapy (both plasma exchange and plasma infusions), prednisone, intravenous immunoglobulin, and antiplatelet agents. Twelve patients achieved remission (92.3%). One patient died from cerebral hemorrhage. Vincristine was administered to 5 patients who did not respond after the first two plasmaphereses. Splenectomy was performed in a patient who relapsed four times within a 2-year period. From the 12 patients achieving remission, 11 have been still in remission for a period of 3 to 69 months.