The metabolic syndrome is a cluster of several vascular risk factors (impaired glucose metabolism, dyslipidaemia, hypertension and central adiposity). The prevalence of the metabolic syndrome is high, varying between 10 and 40% depending on age and sex. This prevalence will increase in the years to come due to the increased prevalence of overweight/obesity. To identify the metabolic syndrome, there is a readily applicable definition for daily clinical practice, i.e. the presence of three or more of the following characteristics: hyperglycaemia, hypertension, low plasma HDL cholesterol level, high plasma triglyceride level and central adiposity. The underlying pathophysiology is not fully clarified, but insulin resistance plays an important role in this syndrome. The metabolic syndrome is associated with increased cardiovascular morbidity and mortality and an increased risk for the development of diabetes mellitus type 2. In subjects with one or two components of the metabolic syndrome and in patients with manifest vascular disease, it seems advisable to be alert to the presence of the other components in order to either diagnose or exclude the metabolic syndrome. Although clinical evidence is lacking, from a pathophysiological point of view it seems reasonable to focus the treatment on reducing insulin resistance, which can be achieved by weight reduction and an increase in physical activity. Treatment of the individual risk factors may also be considered, depending on the degree of vascular risk.