Due to improved surgical techniques and more efficient decision making in treating severely injured patients, survival rates have increased over the years. This study was initiated to evaluate the incidence and identify risk factors for developing posttraumatic stress symptoms, using both extensive trauma-related data and data assessing the psychological trauma, in a population of severely injured patients.79 patients admitted to the Department of Multitrauma and Spinal Cord Injury at Sunnaas Rehabilitation Hospital from 2003 to 2005, prospectively completed semistructured psychological interviews and questionnaires, such as Impact of Event Scale-Revised. In addition, extensive injury-related data, such as injury severity score (ISS), new injury severity score (NISS), and probability of survival (PS) were collected.39% had multiple trauma, 34% had multiple injuries including spinal cord injuries, and 27% had isolated spinal cord injuries. Mean NISS was 31.5 (S.D. 13.7). 6% met diagnostic criteria for posttraumatic stress disorder (PTSD) and 9% met the criteria for subsyndromal PTSD. Injury-related data did not influence the prevalence of posttraumatic stress symptoms, however, some psychosocial variables did have a significant impact.We found a low incidence of PTSD and subsyndromal PTSD. No significant differences were found between the patients suffering from posttraumatic stress symptoms and the non-symptoms group in relation to injury-related data such as ISS/NISS, PS, or multiple trauma versus spinal cord injury. The most evident risk factors for developing posttraumatic stress symptoms were symptoms of anxiety, female gender and negative attitudes toward emotional expression.