Although physicians have been described as "reluctant partners" in reporting medical errors, this survey of 1,082 U.S. physicians found that most were willing to share their knowledge about harmful errors and near misses with their institutions and wanted to hear about innovations to prevent common errors. However, physicians found current systems to report and disseminate this information inadequate and relied on informal discussions with colleagues. Thus, much important information remains invisible to institutions and the health care system. Efforts to promote error reporting might not reach their potential unless physicians become more effectively engaged in reporting errors at their institutions.