Recent scholarship on traumatic stress has suggested that particular types of traumatic stressors may result in different patterns of posttraumatic stress disorder (PTSD) symptoms. Specifically, traumatic stressors that are interpersonal and involve betrayal have been found to be particularly detrimental to youths' psychological functioning. In addition, the extent to which youth experience emotion dysregulation (ED) has been demonstrated to mediate the association between betrayal trauma and PTSD. However, research has yet to disentangle whether betrayal trauma impacts specific facets of ED and PTSD symptoms. Elucidating the specific connections between these constructs is important to our understanding of the impact of betrayal trauma on youth development, and could aid in the development of more targeted interventions for traumatized youth. Thus, the current study sought to examine whether facets of ED mediated the association between traumatic experiences characterized by betrayal versus nonbetrayal and PTSD, and whether these associations were consistent across gender. Participants included 845 detained adolescents (220 girls) aged 12-19 (M ϭ 16.12, SD ϭ 1.29). Youth self-reported lifetime trauma exposure, past-month Diagnostic and Statistical Manual for Mental Disorders-Fifth Edition (DSM-5) PTSD symptoms, and distinct facets of ED. Results suggested several facets of ED were implicated in the association between betrayal and nonbetrayal trauma exposure and specific symptoms of PTSD. Furthermore, few gender differences were observed, suggesting overall similar impacts of trauma exposure on both girls' and boys' emotion regulation capabilities. Results highlight the utility of examining facets of ED from both research and clinical perspectives. Future research should continue to investigate the relation between emotion dysregulation and PTSD in at-risk youth.