A 44-year-old man with splenectomised refractory autoimmune thrombocytopenic purpura (AITP) of 10 years' duration underwent an autologous, T cell-depleted marrow transplant following conditioning with thiotepa and CY. There was no response to the transplant procedure. This is the fourth case in the literature to show failure following autologous stem cell transplantation, although complete, steroid-independent remissions were obtained in the first two patients for over 1 year.