In this article, the authors report on how house officers cope with their medical mistakes and how different coping strategies lead to changes in practice or emotional distress. An anonymous questionnaire requested that house officers report on the most important mistake and their response to it. Analysis of the results revealed that house officers who accept responsibility for their actions are more likely to make constructive changes in their practice but experience greater emotional distress. Escape-avoidance coping mechanisms resulted in defensive changes in practice. The authors conclude with suggestions for medical educators to help residents handle serious medical mistakes.