The aim of this study was to evaluate the structure of posttraumatic stress reaction factors and their relation to general mental health problems in Norwegian children exposed to the tsunami on December 26, 2004. A total of 133 children and adolescents (ages 6-17) were interviewed 10 months posttsunami using the UCLA PTSD Reaction Index, and 104 were interviewed again 2.5 years after the tsunami. Confirmatory factor analyses supported the theory of a four-factor model of intrusion, active avoidance, numbing, and arousal as a better division of symptoms than the three-factor model used in the present diagnostic criteria. The factors of intrusion and active avoidance were highly correlated 2.5 years posttsunami. This association may be due to nonspecificity in these trauma-related factors as posttraumatic stress reaction levels diminish over time. General mental health problems were highly related to arousal at both assessments, supporting the theory that some symptoms of posttraumatic stress reactions overlap with other, concurrent mental problems. (Contains 4 tables.)