The lack of health insurance coverage could be a potentially important deterrent to the use of preventive health care by older adults with high rates of chronic co-morbidities. We use survey data from 12 100 Mexican adults ages 50 and older who participated in the 2001 Mexican Health and Aging Study (MHAS) to analyze the relation between health insurance coverage and the use of preventive health-care services in Mexico. Uninsured adults were less likely to use preventive screenings for hypertension, high cholesterol, diabetes and (breast, cervical and prostate) cancer than insured adults. After adjusting for other factors affecting preventive care utilization in a logistic regression model, we found that these results still hold for high cholesterol and diabetes screening. Similar results hold for the population not working during the survey week and for adults earning below 200% of the poverty line. Our results suggest that insured adults are in a relatively better position to detect some chronic diseases – and have them treated promptly – than uninsured adults because they have better access to cost-effective preventive screenings. Recent public policy initiatives to increase health insurance coverage rates in Mexico could lead to substantially higher preventive health-care utilization rates and improvements in population health. Copyright © 2007 John Wiley & Sons, Ltd.