A questionnaire measuring social sharing of emotion, coping, intensity of emotions and rumination related to March 11th (2004) terrorist attacks in Madrid, emotional climate, social integration, and post-traumatic growth was completed by 644 students and their relatives (38%) in 5 Spanish regions and 8 universities 1 week, 3 weeks, and 8 weeks after the terrorist act. Results supported a two-sided model of the effects of social sharing of emotion derived from Durkheim's classic model of the social functional effects of collective remembering. Higher levels of sharing initially predicted (1) higher event-related emotional arousal and mental rumination and (2) superior social integration and well-being assessed in later weeks. Structural equation modeling showed that higher levels of initial sharing and coping by search for social support predicted directly or indirectly (1) higher social integration (2) higher perceived post-traumatic growth, and (3) higher perceived contentment, hope, solidarity, and confidence in the emotional climate. Copyright © 2009 John Wiley & Sons, Ltd.