One way of understanding the impact of traumatic events is through exploration of cognitive changes that confront a traumatized individual. The author investigated changes in individuals' basic assumptions after traumatic experiences. The participants were 65 people who had been traumatized by representatives of the South African apartheid government. From the total sample, 36 participants had witnessed the violent death of a close relative (sibling, mother, or father). The remaining 29 had been tortured and detained. The author administered the World Assumption Scale (R. Janoff-Bulman, 1989), a semistructured questionnaire on basic assumptions developed for the present study, and the Post-Traumatic Stress Disorder Clinical Checklist (American Psychiatric Association, 1994). Traumatic events affected the participants' basic assumptions about the meaning and benevolence of the world. The tortured and detained group and the bereaved group showed differences in their assumptions of self-worth following the trauma. Cognitive approaches can yield invaluable therapeutic insights into strategies for coping with trauma.