This study offers a developmentally sensitive conceptual understanding of trauma by viewing posttraumatic stress disorder (PTSD) through the lens of social cognition. First, we justify our focus on social cognition by examining the literature on problematic interpersonal relationships associated with PTSD. Next, we link impaired social cognition to the developmental compromise of mentalizing capacity in attachment relationships. We then integrate the diverse research literature into a social-cognitive model of the development of PTSD. We finally conclude by suggesting directions for future research, as it might be shaped by trends in social-cognitive neuroscience.