Purpose: Personality characteristics, including resilience, are understood to be among the factors determining the occurrence of negative consequences of exposure to trauma. The aim of the study was to establish the relationship between type D personality, resilience and symptoms of post-traumatic stress disorder (PTSD) in adolescents exposed to traumatic experiences, including the mediating role of resilience itself. Methods: The study involved 110 adolescents aged 17-18 years, of whom 99 (90%) declared experiencing at least one traumatic event in their lives. This group included 57 boys and 42 girls. Four measurement tools were used in the research, i.e. the Life Events Checklist (LEC-5), the PTSD Checklist for DSM-5 (PCL-5), the Type D Scale (DS-14) and the Resilience Assessment Scale. Results: The most frequent traumatic events reported by the examined adolescents were: transport accident, fire/explosion, and physical assault. Slightly more than 21% of respondents were revealed as having a high probability of developing PTSD symptoms. Both dimensions of type D personality, i.e. negative affectivity and social inhibition, are negatively related to resilience and positively with PTSD-the strongest with negative changes in the cognitive and emotional sphere. Resilience is negatively associated with PTSD and plays a mediating role in relation between social inhibition and PTSD. Conclusions: Reducing the severity of negative affectivity and social inhibition and increasing resilience may reduce the level of PTSD symptoms in adolescents exposed to the trauma.