The clustering of cardiovascular risk factors, known as the metabolic syndrome, greatly increases the risk of developing diabetes, kidney disease, and cardiovascular disease. Individuals with the metabolic syndrome are also at increased risk for premature death from cardiovascular disease or all-cause mortality. Cross-sectional and longitudinal epidemiologic studies provide prevalence data on the syndrome based on criteria proposed by the World Health Organization and the National Cholesterol Education Program Adult Treatment Panel III. Owing to differences in the criteria, estimates of the prevalence of the syndrome vary according to the criteria used. Generally, the syndrome is more common in older people and in the United States and it is more prevalent among Mexican Americans. Obesity and sedentary lifestyles are major contributing factors to the syndrome and provide opportunities for interventions. Recent data from a randomized controlled trial indicate that a weight loss and exercise intervention reduced the incidence of the metabolic syndrome by 41% among individuals with impaired glucose tolerance. Pharmacologic treatment of the individual components of the metabolic syndrome provides an alternate strategy for managing the syndrome. The rising global epidemics of overweight and obesity will likely lead to increases in the prevalence of the metabolic syndrome posing a serious burden for clinicians and public health officials.