The authors estimated stroke frequency in Europe using data from six population-based studies that were analyzed separately and also pooled. Overall, these surveys comprised 19,132 individuals age 55 years and older for the prevalence analyses, and 35,577 person-years for the incidence analyses. The overall prevalence of stroke, age- and sex-adjusted to the 1991 European population, was 4.84% (95% CI 4.47 to 5.21) in individuals age 65 to 84 years and 7.06% (95% CI 6.52 to 7.60) in those 75 years and older. Age- and sex-specific rates did not differ substantially across the studies. Incidence rates of first-ever stroke rose markedly with age, and the pooled results confirmed that incidence keeps increasing even at 90 years of age and older. The overall age- and sex-standardized incidence rates were 8.72 per 1000 person-years (95% CI 7.47 to 10.06) for individuals age 65 to 84 years, and 17.31 per 1000 person-years (95% CI 14.79 to 20.02) for those age 75 years and over.