BACKGROUND: re-hospitalisation after discharge following index stroke varies over time and with age and comorbidity. There is little knowledge about whether stroke unit care reduces the need of re-admissions. OBJECTIVES: to examine whether stroke unit care as compared with care in general medical wards was associated with fewer re-hospitalisations for conditions judged to be secondary to acute stroke and to identify the influence of stroke severity on re-admission rates. DESIGN:we conducted a one-year randomised study to compare the outcome of treatment at an acute stroke unit in a care continuum with the outcome of treatment at general medical wards. SETTINGS: acute and geriatric hospitals in Göteborg, Sweden. SUBJECTS: 216 elderly patients aged >or=70 years discharged to their own homes or to institutionalised living after index stroke. METHODS: comparison of comorbidity classified according to Charlson's morbidity index, re-admission rates, length of hospital stay, number of re-admissions and diagnoses between a group treated at a stroke unit and a group treated at general wards. RESULTS: the re-admission rates, length of hospital stay and causes of re-admissions did not differ between the two groups. Complications related to the damage to the brain and concomitant heart disease were the most common causes of re-admissions in both groups. Index stroke severity did not influence the re-admission rates. CONCLUSIONS: re-admissions for conditions judged to be secondary to acute stroke were equal in the two groups in this prospective study.