A 60‐yr‐old female presented with typical thrombotic thrombocytopenic purpura (TTP). She remained in coma with frequent seizures for 1 wk, with persisting severe thrombocytopenia and microangiopathic haemolytic anaemia, despite treatment with prednisolone, plasma exchange, fresh frozen plasma, sulphinpyrazone and dipyridamole. Splenectomy induced haematological improvement within 1 d, there was cessation of fitting after 2 d, and full neurological recovery ensued over 3 wk. Laboratory studies did not reveal the presence of a platelet‐aggregating factor (PAF), stated to be present in some two‐thirds of cases. While plasma exchange and plasma infusion are beneficial in many cases, splenectomy appears still to be of value in unresponsive