SummaryWe report the cases of two patients who experienced a poorly known adverse effect of bromocriptine—alopecia. The first patient was an infertile 34-y ear-old woman treated with 2.5 mg of bromocriptine per day. The second patient was a 45-year-old woman with Parkinson's disease treated with 40 mg of bromocriptine per day. In both cases there was no preexisting hair loss. Hair loss ceased when bromocriptine was withdrawn and was not attributed to another etiology. Pathophysiological mechanisms are unknown.