If an outpatient repeatedly sees the same practitioner, is his care influenced? This double-blind randomized trial examines the effects of outpatient health care provider continuity on the process and outcome of the medical care for 776 men aged 55 years and older. Participants were randomized to two different groups of provider care: provider discontinuity and provider continuity. The outcome of the continuity group was significantly different from that of the discontinuity group. During an 18-month period, patients who had been randomized to the continuity group had fewer emergent admissions (20% v 39%) and a shorter average length of stay (15.5 v 25.5 days). These patients also perceived that the providers were more knowledgeable, thorough, and interested in patient education. We conclude that continuity of outpatient provider care for men aged 55 years and older results in more patient satisfaction, shorter hospitalizations, and fewer emergent hospital admissions.