Introduction Earthquakes, one of the major natural disasters, tend to be unpredictable, uncontrollable, and highly destructive. They lead to strong initial trauma and significant long-term effects such as posttraumatic stress disorder, depression, anxiety, or other symptoms. Objectives In this research, posttraumatic stress, anxiety and depressive symptoms were studied among adolescents 6 months after Van-Ercis Earthquake 2011. Method In the present study a total of 738 Turkish high school students, aged 13-17 years, participated in the study in Van city affected severely by the earthquake. Participants completed a set of questionnaires including the demographic measures, posttraumatic stress reactions, depression, anxiety and dissociation. Results The results of the present study showed the presence of probable diagnosis of PTSD in 295 (40.69%), of anxiety in 384 (53.04%) and of depression in 245 (33.70%) of the adolescent examined. Multiple logistic and linear regression analyses were conducted to explore the predictive values of independent variables on development of posttraumatic, anxiety, depressive, and dissociative psychopathology among adolescents experienced Van earthquake. Conclusions Our results show high rates of PTSD, anxiety and depression symptoms in adolescents who survived the October 2011 Van-Ercis earthquake. Further, our results highlight the relevance of gender differences, previous psychopathology, trait anxiety, anxiety sensitivity in the response to mass trauma that should be taken into account when facing such events. Our results confirm the pervasive effects of a disaster and risk factors, such as an earthquake, for mental health in adolescents.