Whereas developed nations have witnessed a drop in the occurrence and mortality of ischemic heart disease, developing nations have recorded a constant rise. The burden of cardiovascular disease risk factors may explain this increase. We conducted a population-based cross-sectional survey to estimate the prevalence of cardiovascular risk factors in the population protected by the Mexican Social Security Institute. A total of 20,062 Mexicans, aged >or=20 years, 43.5% (8,727) male and 56.5% (11,335) female, randomly selected in a 4-stage stratified population-based sampling process were included. The most prevalent cardiovascular risk factor in men was smoking (31.9%), whereas in women, it was obesity (26.6%) and central obesity (49.7%). A similar high age-adjusted prevalence was observed in women and men for hypertension (29.7% and 28.8%), diabetes (12.94% and 12.66%), and hypercholesterolemia (13.81% and 12.36%). There was a clear age effect on the prevalence of diabetes, hypertension, and hypercholesterolemia, with increasing prevalence with aging. Smoking also had an age effect, but its prevalence increases as age diminishes. More than half of the subjects in reproductive age (20-44 years old) have at least 1 cardiovascular risk factor, mainly smoking. Cardiovascular risk factors are highly prevalent in the Mexican population, which seems to be between the second and third stages of the tobacco epidemic. The increased prevalence of risk factors clustering indicates the need for comprehensive integrated management of cardiovascular risk factors in Mexicans, with special emphasis on individuals at younger ages. Copyright 2010 Mosby, Inc. All rights reserved.