Individuals who dissociate at the time of a traumatic event (peritraumatic dissociation) are more likely to develop acute and chronic posttraumatic stress disorder (PTSD). However, little is known about who is at risk of peritraumatic dissociation. Motor vehicle accident subjects (N= 122) were systematically recruited and followed over 12 months. We used the Structured Clinical Interview for DSM-III-R (SCID) and the Peritraumatic Dissociative Experiences Questionnaire-Rater Version (PDEQ-RV). Younger subjects were more likely to experience peritraumatic dissociation as were white versus nonwhites, and single versus married subjects. Younger subjects reported a greater number of peritraumatic dissociative symptoms as did subjects with an injured passenger. After adjusting for age and passenger injury, prior major depression was significantly related to more peritraumatic dissociative symptoms. An interaction of age and prior major depression indicated that those who were younger and reported a history of major depression had the greatest number of peritraumatic dissociative symptoms.