This paper describes an adaptation of behavioral activation (BA) for the early intervention of posttraumatic stress disorder (PTSD) and depression among physically injured survivors of traumatic injury, and presents pilot data on a small randomized effectiveness trial (N = 8). The application of BA to PTSD is based on the theory that increases in guided activity may break patterns of avoidance that can maintain PTSD. Compared to treatment as usual (TAU), those who received BA showed improvement in PTSD symptom severity from pre- to posttreatment, and there was a trend for the BA group to score better than the TAU group on physical functioning. Contrary to expectation, this brief adaptation did not have an impact on depression. Implications of these results for the effective early intervention after trauma are discussed. (Contains 4 tables.)