The recommended model for patient participation in medical decision-making is the shared decision-making model (SDM). That model is ambiguous as to how much physician influence on patient decision-making is desirable or permissible. Most discussants suggest that physician influence on medical decisions, while allowable, should be limited. Empirical studies of medical decision-making have shown that much medical practice does not conform to the SDM. The author recommends a different model for medical decision-making, “professional norm-guided medical decision-making,” which, he suggests, much medical practice actually follows. This model does not defer to patient autonomy to the extent usually recommended by the SDM and permits a greater degree of physician influence on patient medical decisions than usual versions of that model. Having described the working of the the professional norm-guided decision-making model, the author specifies the form of patient autonomy respected by it and offers a case for preferring this model of medical decision-making to the SDM.