Resources used to provide health care are vast but not limitless. When clinicians are asked to participate in decisions for large groups of patients (in a managed care context, in an institution, or at the level of local health authorities), the balance between consumption of resources and the benefits of an intervention is important. Clinicians may use cost-effectiveness and cost-benefit studies to inform such decisions (but not to make them). Because of differences in methods, the presentation of results, and country-specific parameters, economic evaluations of the same vaccination strategy by different groups may have divergent results. In this article, we review methodologic issues, limitations, and ethical considerations related to economic evaluations of immunization strategies, focusing on immunizations associated with travel.