Given the rise in health care-related expenditures, decision-makers are increasingly relying on both clinical effectiveness and economic efficiency when making health care decisions. The field of infection control is not immune to this rise in cost-consciousness among health care managers. This article clarifies the role of economic evaluation within infection control for both the user and producer of economic evaluations in this field. The strengths and drawbacks of the several different types of economic analysis--cost minimization, cost-effectiveness, cost-benefit, and cost utility analysis--will be discussed. Additionally, the important features of two specific methods used for economic evaluation-decision analytic modeling and economic analysis alongside a clinical trial-will be outlined. Finally, the criteria by which economic analyses should be judged will be provided. As economic evaluation and health services research continue to play an increasingly important role in health care, it will be vital for infection control advocates to partner with individuals from diverse fields to give decision-makers the type of information they need to make choices.