In a randomized controlled trial we compared the clinical outcome of acute stroke patients, 110 of whom were allocated to treatment in a stroke unit and 110 to treatment in general medical wards. No significant difference existed between these groups with regard to sex, age, marital status, medical history, or functional impairment on admission. Outcome was measured at 6 and 52 weeks after the stroke by the proportion of patients at home, the proportion of patients in an institution, the mortality, and the functional state. After 6 weeks 56.4% of the patients randomized to the stroke unit and 32.7% of the patients randomized to the general medical wards were at home (p = 0.0004), and after 52 weeks 62.7% and 44.6%, respectively, were at home (p = 0.002). After 6 weeks 36.3% of the patients from the stroke unit and 50.0% from the general medical wards were in an institution (p = 0.02); after 52 weeks 12.7% and 22.7%, respectively, were institutionalized (p = 0.016). After 6 weeks mortality was 7.3% for the stroke unit group and 17.3% for the general medical wards group (p = 0.027). After 52 weeks mortality was 24.6% for the stroke unit group and 32.7% for the general medical wards group (difference not significant). Functional state was significantly better for patients treated in the stroke unit after both 6 and 52 weeks. We conclude that care of patients with acute stroke in a stroke unit improves clinical outcome compared with treatment in general medical wards.