<p>Research on complex posttraumatic stress disorder (CPTSD) among individuals with refugee backgrounds is limited, and its validity within this group remains underexplored. This study aimed to assess the prevalence and discriminant validity of posttraumatic stress disorder (PTSD) and CPTSD, as well as the risk factors for CPTSD, in a community sample of adolescents with refugee backgrounds residing in Sweden.&#xa0;This study involved 296 adolescents. Probable diagnoses were evaluated according to DSM-5 and ICD-11 criteria. Latent class analysis was employed to examine the discriminant validity of PTSD and CPTSD, while logistic regression analysis was used to explore risk factors for CPTSD.&#xa0;The findings indicated that 24.1% had a probable diagnosis of PTSD according to the DSM-5. For ICD-11, the equivalent proportions were 7.1% for PTSD and 10.8% for CPTSD. Latent class analysis identified three distinct classes: Low symptoms (46.9%), PTSD (29.6%), and CPTSD (23.6%). Compared to the PTSD class, membership in the CPTSD class was predicted by exposure to more types of violence and child maltreatment. It was also associated with higher posttraumatic stress symptoms, worse general functioning, poorer mental well-being, increased suicidal thoughts, more treatment-seeking behavior, and greater comorbidity.&#xa0;This study found a high prevalence of PTSD and CPTSD among adolescents with refugee backgrounds living in Sweden. Distinct classes aligned with the ICD-11 formulation of PTSD and CPTSD were identified, with exposure to violence and child maltreatment emerging as key risk factors for CPTSD. Results underscore the importance of identifying and addressing posttraumatic stress in adolescents with refugee backgrounds. Future research should aim to further validate the CPTSD diagnosis in larger samples of adolescents with refugee backgrounds.</p>