Metabolic syndrome patients are at increased risk for developing cardiovascular morbidity and mortality. The increasing prevalence of the metabolic syndrome in various asymptomatic populations has been well documented, however, limited information is available about the prevalence in manifest atherosclerotic vascular disease patients. The aim of this study is to determine the overall and gender-specific prevalence of the metabolic syndrome and its components in these patients. This cross-sectional survey of 1117 patients, aged 18-80 years, mean age 60+/-10 years, comprised patients with coronary heart disease (n=527), cerebrovascular disease (n=258), peripheral arterial disease (n=232) or abdominal aortic aneurysm (n=100). Metabolic syndrome was defined by Adult Treatment Panel III. The prevalence of the metabolic syndrome in the study population was 46%: 58% in PAD patients, 41% in CHD patients, 43% in CVD patients and 47% in AAA patients. Overall, women had a higher prevalence than men (56% versus 43%). Age did not influence the metabolic syndrome prevalence; crude odds ratios (crude OR) 1.00 (95% CI: 0.99-1.02). Our results demonstrate a high prevalence of the metabolic syndrome in patients with manifest atherosclerotic vascular disease. Screening for metabolic syndrome in patients with high risk for new vascular incidents may identify patients with even higher vascular risk and may direct anti-atherosclerotic treatment in order to prevent new vascular incidents in the same or another vascular bed.