Eight deaths that occurred during Upjohn-sponsored clinical trials of topical minoxidil and two deaths in subjects who used extemporaneous formulations of the drug are summarized. Of the eight patients in clinical trials, five had cardiovascular abnormalities and two had acquired immunodeficiency syndrome-related pneumonia. One patient died of a self-inflicted gunshot wound. One of the subjects who was using extemporaneous topical minoxidil had hypertension and arteriosclerotic disease and the other died of a myocardial infarction. There is little likelihood of significant adverse effects attributable to topical minoxidil because of its low systemic absorption. The evidence suggests that these deaths were the result of causes other than use of the drug.