We prospectively studied 33 patients with micturition syncope. Of these, eight were young (mean age, 25 years), healthy individuals whose diagnostic evaluation gave normal findings. The remaining 25 patients were older (mean age, 60 years), and 16 were women. This group had an average of 3.8 acute and chronic illnesses per patient, and was taking 3.5 medications per patient. Physical examination disclosed orthostatic hypotension in 22 of these 25 patients. Therapy was directed at improving orthostasis. Over a mean of 15.3 months, no recurrent micturition syncope or sudden death occurred in the entire group. We conclude that there are two groups of patients with micturition syncope. A group consisting of young healthy men has been well described previously. Our larger group, however, consisted of older patients, more often women with multiple illnesses and the majority having orthostatic hypotension.