Posttraumatic stress was assessed in 114 motor vehicle accident (MVA) victims within 2 weeks of hospital admission. Approximately one third of patients reported high levels of posttraumatic stress anxiety. Intrusion symptoms were best predicted by fear of the MVA and absence of head injury. Avoidance symptoms were best predicted by fear of the accident and recent stressful events. Findings indicate that intrusion and avoidance responses to trauma are mediated by different patterns of injury-related and response-related factors.