Bupropion is an antidepressant, thought to be an indirect dopaminergic agonist. No significant sympathomimetic, anti-cholinergic, or MAO inhibitor effects have been reported. We evaluated this drug in 20 patients with idiopathic Parkinson's disease. Parkinsonism lessened by at least 30% (Northwestern University Disability Scale or Modified New York University Parkinson's Disease Scale) in half the patients. Depression, present in 12 of 20, was alleviated in only 5. Bupropion is mildly efficacious in Parkinson's disease, although side effects were frequent and were dose-limiting in five patients.