The present study examined individual and contextual factors associated with posttraumatic stress symptoms in military personnel (N = 122) at 2-3 weeks, 4 and 12 months following two fatal training accidents. PTSD symptoms were reduced after both units had received early psychosocial intervention and continued to perform their operational duties. Examination of individual cases showed a stable low or declining trend in 77% participants, while 23% revealed a stable high or increasing trend in PTSD symptoms over time. PTSD symptoms at 2-3 weeks were associated with trauma exposure, social role in the organization, and avoidance focused coping. Trauma exposure, social role in the organization, and intrusion symptoms at 2-3 weeks, explained 36% of the variance in PTSD-symptoms at 4 months. Previous accidents, emotion focused coping, and avoidance symptoms at 2-3 weeks and 4 months explained 40% of the variance in PTSD-symptoms at 12 months. The results are interpreted within a cognitive processing framework, and the study points out the importance of early assessment of posttraumatic stress symptoms, appraisal and coping responses in professional units exposed to fatal accidents in their line of duty (C) 2002 Elsevier Ltd. All rights reserved.