Physicians are faced with a burgeoning literature of economic studies. However, most physicians have little training in evaluating economic research. Economic studies involve a comparison of the costs and benefits of alternative treatment options. To be of use for medical decision making, they should meet appropriate methodological standards. These include clear specification of the research question and the perspective from which the study is being undertaken, comparison of relevant treatment options, identification and quantification of all important costs and benefits, the use of discounting to allow for time preferences for costs and benefits, and sensitivity analyses to test the robustness of the study's results. Unfortunately, not all adhere to these principles. Physicians need to be able to understand and critically assess the quality of economic studies, and the applicability of the results to their own situation, in order to participate in medical policy decisions.