The study purpose was to determine the extent of neuroleptic exposure in bipolar outpatients maintained on mood-stabilizing medications and any clinical correlates associated with this exposure. Data on medication and severity of illness were gathered from the records (prospective and retrospective) of 70 bipolar patients involved in outpatient research studies at the National Institute of Mental Health (NIMH). The percentage of patients requiring neuroleptic treatment, percentage of time on neuroleptics during the period of observation, total dose of neuroleptics in chlorpromazine (CPZ) equivalency, and number of neuroleptic trials were among the variables calculated. Regression analyses and analyses of variance (ANOVAs) were performed to assess the relationships between neuroleptic exposure and clinical course. Forty-five patients (64.3%) had a neuroleptic trial during the prospective study. Subjects exposed to neuroleptics spent, on average, 15.4% (median, 6.0%) of the time in study on neuroleptic treatment, and were administered, on average, a total of 11,770.5 mg (median, 1,621.9 mg) of neuroleptics (in CPZ equivalency) per year in the prospective study. As expected, bipolar I compared with bipolar II patients had significantly higher neuroleptic exposure by a number of measures. The number of hospitalizations for mania prior to study entry was associated with greater prospective neuroleptic use during the study. Despite maintenance treatment with one or more moodstabilizing agents, we found a relatively high need for adjunctive neuroleptic medication even in this sample of high-functioning bipolar outpatients. These results highlight the need for the study of alternatives, as well as more effective primary mood-stabilizing agents.