The mainstay of treatment for thrombotic thrombocytopenic purpura (TTP) is plasma exchange (PE), but the role of splenectomy is still undefined. The records of all patients with TTP at a single center over a 20-year period were retrospectively reviewed. Response to plasma exchange was determined. The outcome of patients treated with splenectomy in the setting of TTP was evaluated. Sixty-one patients had been treated for TTP. Thirty-nine patients (64%) achieved complete remission (CR) with PE, nineteen (31%) of these achieving sustained CR and seventeen (28%) with relapsed TTP. Twenty patients (33%) had PE refractory TTP and two patients (3%) had PE dependent TTP. During this time period, 10 patients (16%) underwent splenectomy, four patients (7%) for PE dependent TTP, three (5%) for relapsed TTP, and three (5%) for refractory TTP. All of the patients achieved CR after splenectomy. Two patients who had undergone splenectomy had subsequent relapses, both with previously relapsed TTP. In relapsed patients the relapse rate after splenectomy was 0.27 events per patient year compared to 0.6 events per patient year before splenectomy. Median follow-up after splenectomy was 19 months (range 0.13-90 months). In conclusion, relapses in TTP can be managed successfully with additional PE or with splenectomy. PE dependent or refractory TTP can be successfully treated with splenectomy.