Collective traumas can negatively affect large numbers of people who ostensibly did not experience events directly, making it particularly important to identify which people are most vulnerable to developing mental and physical health problems as a result of such events. It is commonly believed that successful coping with a traumatic event requires expressing one's thoughts and feelings about the experience, suggesting that people who choose not to do so would be at high risk for poor adjustment. To test this idea in the context of collective trauma, 2,138 members of a nationally representative Web-enabled survey panel were given the opportunity to express their reactions to the terrorist attacks of September 11, 2001, on that day and those following. Follow-up surveys assessing mental and physical health outcomes were completed over the next 2 years. Contrary to common belief, participants who chose not to express any initial reaction reported better outcomes over time than did those who expressed an initial reaction. Among those who chose to express their immediate reactions, longer responses predicted worse outcomes over time. Implications for myths of coping, posttrauma interventions, and psychology in the media are discussed. (Contains 2 tables.)