We assessed the direct and indirect economic costs and benefits of the current policy of revaccinating tuberculin-negative schoolchildren in the Czech Republic. The analysis is conducted from the perspective of the payer for health care. In considering whether revaccination should be discontinued, we consistently made assumptions which tend to favor revaccination. The direct costs of revaccination are estimated at Czech Koruna (KCR) 15.0 million (US$0.46 million) annually. The direct benefits are the treatment costs saved for future cases averted by revaccination. These range from KCR 0.5 million (US$0.015 million, ambulatory care, excluding transmission benefits) to KCR 13.7 million (US$0.4 million, hospitalization, including transmission benefits). Costs exceed benefits even if children are revaccinated without prior tuberculin testing. The major indirect cost is the loss of work output attributable to tuberculosis morbidity. Counting the averted loss in output as a benefit does not change the results qualitatively, although there is a 50% chance that the benefits will be greater than costs if treatment continues to be hospital-based. Thus, the costs of revaccination in the Czech Republic are found to exceed benefits over most, plausible variations in parameter values. The cost-benefit ratio is especially large if patients are given ambulatory treatment, as recommended by the World Health Organization.