Victims of an armed robbery are at great risk of psychological distress. This research is a prospective randomized controlled clinical trial of an adapted form of Critical Incident Stress Debriefing (CISD-A) with victims of an armed robbery. The specific goals are to examine whether the CISD-A is superior to the control group in both preventing the development of a posttraumatic stress disorder (PTSD) and attenuating the frequency and severity of posttraumatic stress symptoms. Following pretest, 75 participants were randomly assigned to individual debriefing or to a control group. Results revealed no differences between the CISD-A and the control group in preventing PTSD or attenuating posttraumatic symptoms 1 and 3 months later.