The neural pathogenic mechanisms involved in mediating chronic pain and whiplash associated disorders(WAD) after rear impact car collisions are largely unknown. This study’s first objective was to compareresting state regional cerebral blood flow (rCBF) by means of positron emission tomography with15O labelled water in 21 WAD patients with 18 healthy, pain-free controls. A second objective was toinvestigate the relations between brain areas with altered rCBF to pain experience, somatic symptoms,posttraumatic stress symptoms and personality traits in the patient group. Patients had heightened restingrCBF bilaterally in the posterior parahippocampal and the posterior cingulate gyri, in the right thalamusand the right medial prefrontal gyrus as well as lowered tempero-occipital blood flow comparedwith healthy controls. The altered rCBF in the patient group was correlated to neck disability ratings.We thus suggest an involvement of the posterior cingulate, parahippocampal and medial prefrontal gyriin WAD and speculate that alterations in the resting state are linked to an increased self-relevant evaluationof pain and stress.