Despite improvements in our understanding of the pathophysiology of thrombotic thrombocytopenic purpura (TTP), little data exist regarding the long-term sequelae following a diagnosis of TTP. We present the results of a comprehensive evaluation of neurologic injury that included a magnetic resonance imaging (MRI), a neurocognitive testing, and an evaluation of health-related quality of life. Twenty-seven patients with a history of idiopathic TTP functioning normally in their activities of daily living were recruited from existing patient cohorts at both the Ohio State University (n 5 12) (Columbus) and the University College London Hospitals (n 5 15) (London, UK). Nine of 23 (39%) of the MRI studies were abnormal; 17/27 (63%) patients demonstrated neurocognitive impairment, particularly in tests of visual learning and memory. Health-related quality of life scores were also significantly lower than age- and gender-matched US norms for both the composite mental component score and physical component score. These data suggest that the prevalence of neurologic findings in TTP patients in remission is quite high and is largely undetected by routine clinical evaluations. Further longitudinal study will be required to define the risk for neurologic injury and the long-term prognosis in patients previously diagnosed with TTP.