BACKGROUND. Enforcement programs to halt the sale of tobacco to youths have been implemented across the United States. The potential cost-effectiveness of enforcement was evaluated under a range of assumptions regarding cost and impact.

METHODS. An enforcement model was constructed incorporating quarterly inspections of all tobacco vendors. The cost of discounted years of life saved was calculated using reported values regarding cost and a range of assumptions regarding the impact on youth tobacco use.

RESULTS. Inspecting an estimated 543,000 tobacco outlets would cost up to $190 million annually. Costs range from $44 to $8,200 per year of life saved depending on the discount rate and assumptions regarding cost, and efficacy. To compete in cost-effectiveness with implementing smoking cessation guidelines, enforcement would have to produce a 5% reduction in adolescent smoking at a cost of no more than $250 per vendor.

CONCLUSION. At this level of cost and effectiveness an enforcement program could save 10 times as many lives as the same amount spent on mammography or screening for colorectal carcinoma. A one-cent per pack cigarette tax could fully fund enforcement. Enforcement of tobacco sales laws deserves further study as one component of a multifaceted approach to tobacco use prevention.