Thrombotic thrombocytopenic purpura is a rare, threatening disease characterized by thrombocytopenia, microangiopathic haemolytic anaemia and organ dysfunction, e.g., neurological impairment and renal insufficiency. We describe a patient with neurological impairment mimicking a meningoencephalitis in whom a thorough clinical evaluation along with appropriate laboratory tests led us to identify an underlying thrombotic thrombocytopenic purpura. The successful outcome of this patient was based on plasma exchange and immunosuppressive treatment. Thrombotic thrombocytopenic purpura should be considered in the differential diagnosis of patients presenting with any neurological abnormalities, anaemia and unexplained thrombocytopenia.