This study was conducted to examine the association between posttraumatic stress disorder and mental health status of adolescents exposed to the worst disaster of the century. This study was descriptive, cross-sectional, and correlational. This research was conducted between March 31 and July 1, 2023. The study was conducted with earthquake survivors who migrated from Kahramanmaraş, the epicenter of the earthquake, and Adıyaman and Hatay, the other two cities where it was most effective, to Şanlıurfa. The study was conducted with a total of 947 adolescents. "Personal Information Form,""Child Posttraumatic Stress Reaction Index," and "Symptom Distress Check List- (SCL-90)" were used to collect data. Linear regression method was used in the analysis of the research. Path analysis was performed using PATH analysis. The mean age of the adolescents participating in the study was 16.69 ± 1.41 years. It was found that the Global Severity Index (GSI) of the adolescents was at the pathological level with a mean of 2.36 ± 0.68. Posttraumatic stress reactions of the adolescents who experienced the earthquake was found to explain 97.2% of their mental symptoms (anxiety, depression, somatization, anger-hostility, obsession-compulsion, interpersonal sensitivity, phobic anxiety, paranoid ideation, psychotic symptoms, other problems, and GSI) (p < 0.001). It was found that the age of the adolescents, total number of losses in the earthquake, the time they stayed under the rubble, the time they waited for siblings to be pulled from under the rubble and the state of having loss due to the earthquake explained 74.4% of the posttraumatic stress reactions (p < 0.001). As a conclusion, it was found that the adolescents who experienced the earthquake experienced severe posttraumatic stress symptoms. It was also found that adolescents who experienced high levels of trauma symptoms showed pathological mental symptoms. After the earthquake, adolescents should be evaluated periodically in terms of posttraumatic stress symptoms. In the evaluations to be made, it is important to determine how adolescents are affected especially mentally. In this context, interventions should be implemented for the identified mental symptoms (anxiety, depression, somatization, etc.).