A case of Wernicke's encephalopathy associated with promyelocytic leukemia found at autopsy is reported. The patient was 30 years old and was undergoing chemotherapeutic treatment when she had a memory deficit for recent events (Korsakoff's syndrome) which persisted for 6 months, until death. The neuropathologic examination showed typical, old lesions that characterize Wernicke's encephalopathy, but only in the mamillary bodies. This case is compared with three other cases of Wernicke's encephalopathy associated with leukemia previously described in the literature. Comment is made on the cliniconeuropathologic picture and risk factors in leukemic patients that may favor the appearance of Wernicke's encephalopathy.