Trauma and its effects on early intrapsychic development are issues that need to be better understood as young children are exposed to ever increasing levels of violence. In this paper, we have considered trauma from the perspective of its effects on young children in the context of chronic community and family violence. Characteristic features of adults with post traumatic stress disorder have been identified in children under 4 years old who have been exposed to extreme trauma. In understanding trauma and its effects on children, it is important to consider how external events may impact on intrapsychic structure and the development of the self. A case is presented of identical 2 year, 11 month old twin boys who were referred after having witnessed the shooting death of their mother by their father seven months earlier. The course of psychoanalytically informed play psychotherapy is discussed with a major goal of the therapy being to help the children work through the trauma and return to a healthy developmental course. While the twins responded well to treatment and were able to work through traumatic material, systematic follow-up is needed to determine the later developmental course.