A review of the literature finds a reported incidence of CNS complications from cancer chemotherapy ranging from 5% to 86% for different classes of drugs. Patients receiving cancer chemotherapy are rarely given a systematic psychiatric evaluation, however. Psychiatric sequelae are rarely noted in the absence of neurologic disturbances. Organic mental disorders and affective disturbances are most often noted; acute psychotic reactions are rarely seen. As detailed in this review, most changes appear reversible with the exception of a significant incidence of chronic CNS effects following high-dose intravenous or intrathecal methotrexate therapy.