Benefit-cost analyses hold great promise for influencing policies related to children, youth, and families. By comparing the costs of preventive interventions with the long-term benefits of those interventions, benefit-cost analysis provides a tool for determining what kinds of investments have the greatest potential to reduce the physical, mental, and behavioral health problems of young people. More generally, the growth of benefit-cost analysis as a field of research and practice represents an exciting and promising trend in the development and implementation of public policies. The utility of benefit-cost analyses has been limited by a lack of uniformity in the methods and assumptions underlying these studies. For years, those who perform and those who use benefit-cost analyses have argued that the development and use of theoretical, technical, and reporting standards for benefit-cost analyses would enhance the validity of results, increase comparability across studies, and accelerate the progress of the field. Considerations in Applying Benefit-Cost Analysis to Preventive Interventions for Children, Youth, and Families is the summary of a workshop convened by the Board on Children, Youth, and Families of the Institute of Medicine and the National Research Council in November 2013 as the first phase of a possible two-part effort directed toward guiding future benefit-cost studies and enhancing the relevance of benefit-cost analysis to governments and other organizations wanting to make sound prevention decisions. The workshop brought together leading practitioners in the field, researchers who study the methodological and analytic dimensions of benefit-cost analysis, and representatives of organizations that use the results of benefit-cost analyses to shape and implement public policies. This report discusses a wide range of issues about benefit-cost analysis, including the level of research rigor that should be met before results from an evaluation are used to estimate or predict outcomes in a cost-benefit analysis; best practices and methodologies for costing prevention interventions; prevention outcomes that currently lend themselves to monetization; processes and methodologies that should be used when linking prevention outcomes to avoided costs or increased revenues; and best methods for handling risk and uncertainty in estimates.