OBJECTIVES: To estimate the rate of hospitalizations due to cardiovascular disease and other causes following an acute atherothrombotic stroke and the associated costs. METHODS: We evaluated hospitalization rates (cumulative number divided by the patient time in a given period) following a diagnosis of acute stroke using the health care records of residents of Saskatchewan, Canada who were diagnosed between 1990-1995. Data on patient characteristics and medical history were available from January 1980 and follow-up was complete to December 2000. Costs (2002 Canadian dollars) were also estimated. Reasons for hospitalization were classified on the basis of primary diagnosis, into atherothrombotic (stroke, TIA, myocardial infarction, angina, or other cardiovascular disease), gastrointestinal (GI) bleeding and other. RESULTS: The 18,704 patients with stroke (48% male) tended to be elderly (mean age 70.5 years). Nearly two-thirds died during follow-up. At least 1 hospitalization occurred in 13,952 (72.7%), a hazard of 36.2/100 person years and those hospitalized had 3.9 admissions on average. Atherothrombotic causes were most frequent (82.4%), the majority were stroke and TIA (53.2%), but length of stay was longest for GI bleeds (mean 17.1 days vs 16.1 for atherothrombotic disease). The admission rates due to atherothrombotic disease were 3 times higher in the month following stroke than after the first year; and higher with age greater than 65 years (hazard ratio 1.8, 95% CI 1.69-1.83), diabetes (1.7, 1.62-1.86), atrial fibrillation (2.1, 1.96-2.30), hypertension (1.8 1.65-1.86), heart failure (2.1, 1.97-2.21) and prior atherothrombotic events (1.2, 1.17-1.32). Atherothrombotic hospitalizations accrue costs between $442 per patient per month in the first month to $39 per patient per month after 5 years. CONCLUSIONS: Patients surviving a stroke are frequently readmitted, mostly for atherothrombotic problems, and these events accrue substantial costs, especially early on in the course post-stroke.