Bromocriptine, an ergot alkaloid derivative that possesses both dopamine agonist and antagonist activity, has been studied in a broad spectrum of psychiatric illnesses. The literature consists primarily of case reports and small trials limited by methodological shortcomings. The authors critically review these reports, focusing on efficacy, mechanistic issues, dosing, side effects, predictors of response, monitoring parameters, and practical guidelines. Preliminary data suggest bromocriptine may have promise in the treatment of neuroleptic malignant syndrome, cocaine withdrawal, and depression. At present, the agent appears less efficacious in the treatment of tardive dyskinesia, mania, and schizophrenia; however, doses in these trials may have been excessive, producing primarily postsynaptic agonist effects. More extensive clinical trials are required to clearly define the role of bromocriptine in psychiatry.