Relative value studies are lists of “relative values” of different professional services. Antitrust enforcement agencies recently have filed several complaints against the promulgation of relative value studies by professional organizations of physicians, alleging that these lists have been used to fix and increase physician fees. This article examines the status of professionally sponsored relative values studies under antitrust law and suggests several reasons why they should be held unlawful. In particular, such relative value studies threaten to eliminate desirable competition among private third-party payers in the development of effective cost-containment strategies as well as among physicians in the setting of fees. Moreover, the alleged benefits of professionally sponsored relative value studies could be achieved by alternative means that do not similarly restrict competition in the provision of medical services.