Health care expenses have grown rapidly and are consuming an increasing porportion of the gross national product in the United States as well as in many other countries, on an annual basis. Conservative estimates of the impact of nosocomial infections have shown an important economic influence and account for significant hospital costs. As a result, hospital epidemiologists, given limited financial resources, must expand their efforts to evaluate cost-effective strategies for infection control. Public health priorities and program strategies must be examined in an attempt to maximize the resources available for the overall population. This article reviews the current data on cost and methods for cost analysis, and creatively assesses optimal cost-effective strategies for infection control programs.