Three hundred patients with Parkinson's disease taking dopamine agonists were surveyed for the presence of compulsions. Fifty-eight reported active compulsions which had developed after initiation of dopamine agonists. These included 25 with sexual compulsions and 28 with self-described compulsive gambling, of whom 17 met criteria for pathologic gambling. Males were over-represented. Patients with any compulsion and those with pathologic gambling were about 6 years younger than those without compulsions. These behavioral problems were not associated with an individual dopamine agonist, nor dose or duration, nor concomitant levodopa. Follow-up of the pathologic gamblers 1 year after intervention, which was cessation of the dopamine agonist in most cases, found ongoing but controlled gambling in five and complete cessation within 4 months in the remainder.