Among the adverse mental health consequences of childhood trauma is the risk related to the development of posttraumatic stress disorder (PTSD) in adulthood. Other risk factors for PTSD, including parental trauma exposure and parental PTSD, can also contribute to the experience of child trauma. We examined associations between childhood trauma and PTSD in 51 adult children of Holocaust survivors and 41 comparison subjects, in consideration of parental trauma exposure and parental PTSD. We also examined these variables in relation to 24-hr urinary cortisol levels. Adult offspring of Holocaust survivors showed significantly higher levels of self-reported childhood trauma, particularly emotional abuse and neglect, relative to comparison subjects. The difference was largely attributable to parental PTSD. Self-reported childhood trauma was also related to severity of PTSD in subjects, and emotional abuse was significantly associated with 24-hr mean urinary cortisol secretion. We conclude that the experience of childhood trauma may be an important factor in the transmission of PTSD from parent to child.