Thrombotic microangiopathy (TMA) is an infrequent but serious complication of allogeneic transplantation. The success rate of plasma exchange (PE) reported in the treatment of this entity is a controversial subject. We report the outcome of 10 patients with TMA post-allogeneic transplantation after treatment with PE. Two out of the 10 patients have not responded, five had a partial response, but died of acute GVHD or interstitial pneumonitis, and three have responded and recovered. Our study suggests that there are different degrees of TMA severity. Only mild multifactorial cases with no severe hemolysis (LDH activity <1000 U/l) may be fully resolved with PE.