ENBackground. Complex posttraumatic stress disorder is a new diagnosis in the 11th edition of the International Classification of Diseases (ICD-11). There is a need for a better understanding of complex PTSD in children and adolescents. Objective The study aimed to estimate the factors associated with chronic complex PTSD versus recovery of complex PTSD in adolescents in a 2-year follow-up study. Method. In total, 66 adolescents, mean age 14.5, 73% female, identified as having complex PTSD using self-report at baseline recruited from a general population sample, were included in the study. The International Trauma Questionnaire - Child and Adolescent Version (ITQ-CA) was used for the assessment of complex PTSD. Results. Overall, 36% of the study sample has been identified as having chronic complex PTSD over 2 years, 10% met the criteria for PTSD at a 2-year follow-up, and 54% recovered. A higher risk for chronic complex PTSD was associated with exposure to more traumatic events and more life-stressors over the 2 years, low social network, low positive social support, bullying at school, and loneliness. Conclusion. The study found that around one-third of the traumatized youth had a prolonged trajectory of complex PTSD symptoms, which were associated with negative life experiences and social difficulties. Keywords: Complex PTSD, adolescence, ICD-11, trauma, longitudinal. [From the publication]