The prospective associations between the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP/ATP III) expert panel and mortality from cardiovascular disease and all-causes has not been extensively examined. Using data from the National Health and Nutrition Examination Survey II Mortality Study (1976-1992), the author examined the association between the metabolic syndrome and mortality from all-causes and cardiovascular disease among 2431 US adults aged 30-75 years. The NCEP/ATP III criteria were modified to substitute body mass index >/=25 kg/m(2) for waist circumference for women and >/=30 kg/m(2) for men. After multiple-adjustment, the hazard ratios for participants with the metabolic syndrome were 1.37 (95% confidence interval (CI): 1.02, 1.85) for mortality from cardiovascular disease, 1.29 (95% CI: 0.92, 1.82) for mortality from coronary heart disease, 1.68 (95% CI: 0.86, 3.27) for mortality from stroke, 1.23 (95% CI: 0.95, 1.59) for mortality from diseases of the circulatory system, and 1.15 (95% CI: 0.92, 1.45) for all-cause mortality compared with participants without the syndrome. The association between the number of metabolic syndrome criteria and mortality from cardiovascular disease was near linear (P = 0.007). Three criteria of the syndrome-excess weight, hypertriglyceridemia, and low high-density lipoprotein cholesterol concentration-were not independently associated with any of the outcomes. Additional prospective studies are needed to examine the association between the metabolic syndrome and the incidence of cardiovascular disease and mortality from cardiovascular disease and all-causes.