The objectives were to analyse whether cardiovascular risk factors appear simultaneously in the population and to determine whether it depends on age. The participants belong to a random sample of individuals 25-74 years of age, representative of the non-diabetic population free of coronary heart disease of the province of Gerona, Spain, studied during 1994-1996. Exploratory factor analysis was used to assess clustering of cardiovascular risk factors and confirmatory factor analysis to compare clustering among age groups (25-54 and 55-74). RESULTS: In the 25-54 age group, we observed in both sexes the Central Metabolic Syndrome factor, which included glucose, lipids, and waist-to-hip ratio, and Metabolic Hypertension factor, which included systolic and diastolic blood pressures, waist-to-hip ratio, low-density lipoproteins, glycaemia, and triglycerides. In the 55-74 age group we observed in both sexes the Central Metabolic Syndrome factor, with the same composition as in younger subjects, and Isolated Hypertension factor, composed only of systolic and diastolic blood pressures. In both sexes, the chi2 value for the model of the combined age groups was higher than the sum of chi2 values of the best models for each age group separately (p < 0.01), which indicates that both sexes presented factor structures that differed by age group. CONCLUSIONS: The Central Metabolic Syndrome factor was common to all four sex and age groups studied. In younger subjects blood pressure was related to lipids, obesity, and glycaemia, suggesting the existence of a Metabolic Hypertension factor, while systolic and diastolic blood pressures were found to be the only significant variables in the hypertension factor after 54 years.