Neurological complications in bone marrow transplant (BMT) patients include central nervous system (CNS) infection, seizure, cerebrovascular accidents, and CNS disease recurrence. The purpose of this study was to describe the pattern and distribution of CNS complications and responses during BMT and to describe the presentation and outcome of select neurological incidents. The records of 200 BMT patients undergoing transplantation in 1989 were randomly selected and comprise the sampling unit for this study. Generally, the peak occurrence of CNS complications was pretransplant through day 21 posttransplant. Neuropathy and somnolence occurred earliest, peaking on day —13 and —8 pretransplant, respectively; confusion or disorientation peaked around day 12 posttransplant. Fifteen patients (7.5%) experienced seizure or suspected seizure, principally of the tonic-clonic type. Fifty-two patients (26%) experienced coma or encephalopathy. Etiologies included respiratory compromise, renal failure, and hepatic dysfunction, often occurring simultaneously. Coma and encephalopathy were commonly associated with terminal events. Because nurses are often the first to identify sensory and perceptual alterations in BMT patients, these results may assist nurses in the early detection of CNS complications.