We assessed the impact of the NCEP-III recommendations in a population-based, nation-wide Mexican survey. Information was obtained from 15,607 subjects aged 20 to 69 years. In this report, only samples obtained after a 9 to 12 hours fast are included (2,201 cases). A cardiovascular risk equivalent was found in 10.5% and > or = 2 risk factors were present in 41.7% of the population. In 10% of cases, the LDL-C concentration was high enough to be an indication for a lipid-lowering drug (> 160 mg/dL), independent of the presence of risk factors. A quarter of the population was eligible for some form of treatment (lifestyle modifications in 15.9%, drug therapy in an additional 11.7%). Among cases with > or = 2 risk factors, a small percentage (1.8%) were identified as having a 10 year-risk > 20% and 86.3% were considered as having a 10 year-risk < 10%. The majority of the metabolic syndrome cases (84%) were identified as low-risk subjects. As a result, only 17.6% of them qualified for drug-based LDL-C lowering. Our data helps to estimate of the magnitude of the burden imposed on the Mexican health system, of lowering LDL-C for cardiovascular prevention. If we apply our results to the 2,000 Mexican population census more than 5.8 million cases nationwide may require LDL lowering drug therapy following the NCEP-III criteria.