The prevalence of the metabolic syndrome in different elderly European populations has not been well studied. The aim of this study was to measure the prevalence of metabolic syndrome, as well as its individual components, in an elderly Swedish cohort. A random sample of 778 individuals (372 men and 406 women) was selected from a 70-year-old cohort in the H70 study, a gerontological and geriatric population study carried out in Gothenburg, Sweden. The study included medical and treatment history assessments, laboratory procedures and physical examinations to determine the presence of each of the five components of the metabolic syndrome as defined by the National Cholesterol Education Program Adult Treatment Panel III. Of the 508 adults (243 men and 265 women) included in the study, 22.6% had metabolic syndrome. The prevalence was higher in men (26.3%) than in women (19.2%). One third of the total sample had at least one of the five risk factors for metabolic syndrome. High blood pressure (> or =130/85 mmHg or use of antihypertensive/diuretic medication) was the most prevalent risk factor in both men (68.3%) and women (50.2%), while abdominal obesity was the overall second most common risk factor (27.2% of men and 42.7% of women). The prevalence of high fasting plasma glucose (> or =110 mg/dl or use of antidiabetic medication) was 29.0% in men and 19.1% in women. Metabolic syndrome was prevalent in a significant proportion of this elderly Swedish population, highlighting the underdiagnosis of a condition that is important to treat.