Persistent pain and disability after whiplash trauma has become an increasingly significant problem in many industrialized countries entailing comprehensive individual as well as social costs. The dissertation includes two areas of research within whiplash trauma. The first part contains two empirical articles focusing on risk factors for poor recovery. The second part contains a systematic review and an empirical article and concerns the influence of coping strategies on recovery with a special emphasis on possible gender differences. All empirical articles in the dissertation are based on self-reported questionnaire data on a patient cohort of whiplash-exposed. Patients are consecutively included in the study within the first ten days of collision recruited from emergency departments and general practitioners in four counties in Denmark from April 2001 to June 2003. One of the empirical articles in the dissertation is supplemented with data from a social register of transfer benefits on the patient cohort as well as on a matched register control cohort in the general population. In this dissertation we wish to answer the following questions: 1) Do self-reported pre-collision health-related and socio-demographic factors affect self-reported work capability and neck pain one year after acute whiplash trauma? 2) Do transfer benefits before the accident predict negative change in future health-related provisional situation and future neck pain? 3) Do persons with acute whiplash trauma experience more negative change in future health-related provisional situation compared to a matched register control group? 4) Does research in the use of coping strategies after whiplash trauma show that these predict poor restitution and is there any research on gender differences in the use of coping strategies in whiplash-exposed? 5) Do gender and coping strategies interact in the prediction of future neck pain following acute whiplash trauma? Self-reported unspecified pain, female gender, low educational level, unemployment and blue collar work before the collision predicted future self-reported affected work capacity. Pre-collision self-reported unspecified pain, high psychological distress, female gender and low educational level predicted future self-reported neck pain. Self-reported characteristics before the collision are shown to be important for recovery after acute whiplash trauma. Whiplash exposure was a major risk factor for future negative change in provisional situation as whiplash-exposed more than tripled their risk of negative change in provisional situation compared to matched controls in the general population. Being unemployed, sick-listed, and receiving social assistance pre-accident were all associated with future negative change in health-related provisional situation. Sick-listing before the accident not only predicted negative change in provisional situation, but future neck pain as well. Furthermore, as few as 1-18 weeks of sick-listing within the five years preceding the collision more than doubled the risk of future negative provisional situation. Coping strategies are shown to affect recovery after whiplash trauma, but little information is available about which strategies are adaptive or maladaptive at different times in recovery. However, there is evidence of catastrophizing and reinterpreting pain sensations being maladaptive for patients exposed to whiplash trauma. There was not enough evidence to draw conclusions on the possible impact of gender in the use of coping strategies in patients exposed to whiplash trauma as only six studies contributed with findings, and only two studies treated the subject at some length. No interaction between gender and the five examined coping subscales on future neck pain were found. That is, use of coping strategies three months post-collision did not explain the different prognosis observed in men and women. However, we found that distraction, reinterpreting, catastrophizing, and praying and hoping predicted future considerable neck pain in both men and women. In conclusion, we propose that a complicated interrelationship of various factors before the collision constitutes a pre-disposing vulnerability that may be triggered by the whiplash trauma and act together with multifactorial maintaining factors after the accident in the course of developing persistent pain and disability after whiplash trauma. The findings from our study will make for further research and promote identification of patients at risk and hopefully contribute to preventive interventions and treatment that may decrease impairment in health-related quality of life and persistent symptoms and prevent the social decline that is a risk for some whiplash-exposed. This will in turn result in reduced social and economical costs not only for the individual, but also for society.