Cost data are useful in comparing various health problems, assessing risks, setting research priorities, and selecting interventions that most efficiently reduce health burdens. Using analyses of national and state data sets, this article presents data on the frequency, costs, and quality-of-life losses associated with unintentional childhood injuries in 1996. The frequency, severity, potential for death and disability, and costs of unintentional injury make it a leading childhood health problem. Unintentional childhood injuries in 1996 resulted in an estimated $14 billion in lifetime medical spending, $1 billion in other resource costs, and $66 billion in present and future work losses. These injuries imposed quality-of-life losses equivalent to 92,400 child deaths. Since Medicaid and other government sources paid for 39% of the days children spent in hospitals due to unintentional injuries, the government has a financial interest in, and arguably a responsibility for, assuring the safety of disadvantaged children. Federal agencies, however, devote relatively few public dollars to injury prevention research and programming. Several proven child safety interventions cost less than the medical and other resource costs they save. Thus, governments, managed care companies, and third-party payers could save money by encouraging the routine use of selected child safety measures such as child safety seats, bicycle helmets, and smoke detectors. Yet, these and other proven injury prevention interventions are not universally implemented.