The aim of our study was to evaluate the prevalence of the metabolic syndrome (MBS) according to the current International Diabetes Federation definition in German PCOS women. Four hundred and eleven PCOS patients (age 28�6.3 years) and 82 controls (age 28�7.5 years) were evaluated for anthropometric and metabolic parameters by physical examination, blood testing and a personal interview including family history. A subgroup analysis of controls with BMI-matched PCOS women (BMI 22.9�2.8 kg/m 2) was performed to detect PCOS specific differences in metabolic variables between the groups. The MBS was found in 33.8% of PCOS women compared to 7.3% in the control group. Parameters of insulin resistance, lipid-and glucose metabolism, mean values of all criteria of the MBS as well as the prevalence of the MBS were significantly different between the entire PCOS cohort and controls, but did not differ between BMI-matched PCOS women and controls. In addition, the prevalence of the MBS increased with age. Moreover, in PCOS women an increase in BMI and insulin resistance was accompanied by a further significant increase in the severity of clinical and biochemical hyperandrogenism. In PCOS women, while one out of three PCOS women had the MBS, the presence of metabolic abnormalities did not appear to be associated with PCOS per se, but rather correlated with age and the degree of obesity.