**Research aims** The aim of this study was to investigate the psychometric properties of the CRIES-8 among adolescents from Afghanistan, Syria, and Somalia. First, we (a) tested the model fit of the two-factor structure of the CRIES-8 within each of the three country groups, and (b) the measurement invariance between groups. This way we could evaluate whether the CRIES-8 seems to assess the same dimensions of post-traumatic stress, namely intrusion and avoidance. Also, we could evaluate whether the respondents report symptoms similarly between groups, meaning that indicators have similar loadings on their assumed factors. For robustness of the results, we decided to control for two other invariance tests. We investigated whether the time spent in host country changed the way adolescents responded to CRIES-8 by testing measurement invariance between recently arrived and settled youths. Also, due to unexpected country-specific differences in the response labeling options for CRIES-8 (see: “Measures”), we decided to test the measurement invariance between different response labeling options. Second, we estimated reliability for the intrusion, and avoidance scales, and for the total score among the three country groups. Third, we estimated the symptom prevalence among the three groups.