We evaluated the cost-effectiveness of administering a daily "polypill" consisting of three antihypertensive drugs, a statin, and aspirin to prevent cardiovascular disease among high-risk patients in Latin America. We found that the lifetime risk of cardiovascular disease could be reduced by 15 percent in women and by 21 percent in men if the polypill were used by people with a risk of cardiovascular disease equal to or greater than 15 percent over ten years. Attaining this goal would require treating 26 percent of the population at a cost of $34-$36 per quality-adjusted life-year. Offering the polypill to women at high risk and to men age fifty-five or older would be the best approach and would yield acceptable incremental cost-effectiveness ratios. The polypill would be very cost-effective even in the country with the lowest gross national income in our study. However, policy makers must weigh the value of intervention with the polypill against other interventions, as well as their country's willingness and ability to pay for the intervention.