Objectives:To estimate the excess cost of stroke in Sweden and the potential costs that could be avoided by preventing first-ever strokes. Methods: We adopted the incidence approach for estimating the present value of both direct and indirect costs. Data on mortality, stroke recurrence, and inpatient care were estimated from a national register of patient data with a four-year follow-up period. To estimate costs for social services, we used survey data on living conditions before stroke onset and at three and at twenty-four months. Costs for outpatient visits, rehabilitation, drugs, and production losses due to premature death and early retirement were estimated on the basis of both published and nonpublished sources. Lifetime costs were based on life tables adjusted for excess mortality of stroke, and costs in year 4 were extrapolated to subsequent years. Results: The present value direct cost for an average stroke patient is SEK513,800 (US$56,024 or Euro60,825). The corresponding indirect cost is SEK125,110 (US$13,640 or Euro14,810). Almost 45 percent of the direct costs were attributable to social services. Women had higher costs than men, and costs for survivors increased with age due to social services. Conclusions: With an incidence of 213 first-ever strokes per 100,000 individuals, the total excess direct and indirect cost of stroke would be SEK12.3 billion (approximately US$1.3 billion or Euro1.5 billion). Hence, there are large potential cost offsets both in the health-care sector and in the social service sector if the incidence of first-ever stroke could be reduced.