Objective: To determine whether and how pediatricians would disclose serious medical errors to parents. Design: Cross-sectional survey. Setting: St Louis, Missouri, and Seattle, Washington. Participants: University-affiliated hospital and community pediatricians and pediatric residents. Main Exposure: Anonymous 11-item survey administered between July 1, 2003, and March 31, 2004, containing 1 of 2 scenarios (less or more apparent to the child's parent) in which the respondent had caused a serious medical error. Main Outcome Measures: Physician's intention to disclose the error to a parent and what information the physician would disclose to the parent about the error. Results: The response rate was 56% (205/369). Overall, 53% of all respondents (109) reported that they would definitely disclose the error, and 58% (108) would offer full details about how the error occurred. Twenty-six percent of all respondents (53) would offer an explicit apology, and 50% (103) would discuss detailed plans for preventing future recurrences of the error. Twice as many pediatricians who received the apparent error scenario would disclose the error to a parent (73%  vs 33% ; P<.001), and significantly more would offer an explicit apology (33%  vs 20% ; P=.04) compared with the less apparent error scenario. Conclusions: This study found marked variation in how pediatricians would disclose a serious medical error and revealed that they may be more willing to do so when the error is more apparent to the family. Further research on the impact of professional guidelines and innovative educational interventions is warranted to help improve the quality of error disclosure communication in pediatric settings.