Physician performance failures are not rare and pose substantial threats to patient welfare and safety. Few hospitals respond to such failures promptly or effectively. Failure to ensure the quality and safety of the performance of colleagues is a breach of medicine's fiduciary responsibility to the public. A major reason for this deficiency is the hospitals' lack of formal systems to monitor physician performance and to identify and correct shortcomings. To develop and implement these systems, hospitals need better performance measures and substantial expansion of external programs for assessment and remediation. This is a task well beyond the capacities of individual hospitals; a national effort is required. The authors call on the Federation of State Medical Boards, the American Board of Medical Specialties, and the Joint Commission on Accreditation of Healthcare Organizations (organizations that already bear a fiduciary responsibility for ensuring safe, competent care) to collaborate on developing better methods for measuring performance and to expand programs for helping practitioners who are deficient.