This study examines a pilot school-based treatment program for American Indian adolescents residing on a reservation who presented with symptoms of Posttraumatic Stress Disorder (PTSD) and symptoms of depression. This is the first study directed at treating American Indian children with trauma; seven case studies demonstrate our findings that a manualized cognitive behavior therapy intervention delivered in group format for 10 weeks has potential for helping some children who experience PTSD symptoms and depression. The findings generally replicate previous research conducted with groups of non-Indian adolescents in urban settings. PTSD and depressive symptoms decreased for three of the four students who completed treatment. Directions for future research include the need to understand and control attrition and to address cultural influences, including making adaptations in the cognitive behavioral formulations and techniques regarding feelings as operant behaviors. Results contribute to knowledge of feasibility and acceptability of cultural adaptations of CBT for trauma in an under-served population.