Adolescent girls who have been sexually abused are known to develop PTSD at substantially high rates and display significant impairments in emotion regulation and social competence. In addition, PTSD in adolescence is a powerful risk factor for substance abuse, suicidality, and revictimization in the teen years. Thus, there is a serious public health need to intervene during this period of heightened risk for multiple negative life outcomes. As yet, there is no effective treatment that addresses the multiple needs of adolescent girls with PTSD. We propose to adapt for adolescent girls an empirically validated, manualized cognitive-behavioral treatment that was developed for an ethnically diverse population of women with PTSD related to childhood abuse. The treatment is composed of two sequential components: a ten-session module of skills training in affective and interpersonal functioning (STAIR) and a six-session module of emotional processing of the traumatic events via imaginal exposure (IE). A five-month open-trial period will be designated to complete and refine the treatment adaptation. Assessment of treatment sessions (by video recordings) and weekly case consultation meetings will be used to monitor and document treatment delivery and make necessary changes to the treatment. This effort will be followed by a preliminary randomized outcome study. A total of 74 adolescent girls with a diagnosis of PTSD will be randomly assigned to either the cognitive-behavioral treatment (STAIR/IE) or to an enhanced treatment as usual (E-TAU) that consists of an identical number of sessions in an unstructured format typical of community treatment for traumatized youth. The efficacy of STAIR/IE and E-TAU will be assessed at post-treatment and at three-month follow-up using measures assessing the three targeted outcomes: 1) emotion management skills, 2) social competence and 3) PTSD symptoms.