Does the social scientific study of medicine require a commitment to relativism? Relativism claims that some subject (e.g., knowledge claims or moral judgments) is relative to a background (e.g., a culture or conceptual scheme) and that judgments about the subject are incommensurable. Examining the concept of success as it appears in orthodox and nonorthodox medical systems, we see that judgments of success are relative to a background medical system. Relativism requires the social scientific study of medicine to be value free in the sense that a medical system must be described without evaluating its elements. When social scientists do evaluate the successfulness of a nonorthodox medical system, they give a crucial role to the nonorthodox conception of success. This strategy does not vitiate value-freedom and it entails a relativism about success. The social scientific study of medicine, therefore, does require relativism in the form of a relativism about success.