Background: In response to the report by the Institute of Medicine on medical errors, national groups have recommended actions to reduce the occurrence of preventable medical errors. What is not known is the level of support for these proposed changes among practicing physicians and the public., Methods: We conducted parallel national surveys of 831 practicing physicians, who responded to mailed questionnaires, and 1207 members of the public, who were interviewed by telephone after selection with the use of random-digit dialing. Respondents were asked about the causes of and solutions to the problem of preventable medical errors and, on the basis of a clinical vignette, were asked what the consequences of an error should be., Results: Many physicians (35 percent) and members of the public (42 percent) reported errors in their own or a family member's care, but neither group viewed medical errors as one of the most important problems in health care today. A majority of both groups believed that the number of in-hospital deaths due to preventable errors is lower than that reported by the Institute of Medicine. Physicians and the public disagreed on many of the underlying causes of errors and on effective strategies for reducing errors. Neither group believed that moving patients to high-volume centers would be a very effective strategy. The public and many physicians supported the use of sanctions against individual health professionals perceived as responsible for serious errors., Conclusions: Though substantial proportions of the public and practicing physicians report that they have had personal experience with medical errors, neither group has the sense of urgency expressed by many national organizations. To advance their agenda, national groups need to convince physicians, in particular, that the current proposals for reducing errors will be very effective., (Copyright 2002 Massachusetts Medical Society)