Posttraumatic stress disorder (PTSD) and chronic pain frequently co-occur in everyday clinical practice resulting in negative interreaction for the clinical course, outcome and treatment of either disorder. However, there is no empirical studies investigating theoretical models to explain comorbidity nor well-controlled studies investigating the efficacy of treatments. The authors analysed possible neurobiological interrelationships between chronic pain and chronic PTSD as well as clinical experiences of the assessment and treatment of patients with chronic pain and chronic combat-related PTSD. The 200 patients with chronic combat-related PTSD and chronic pain, who were treated during year 2006, were selected as the sample for this study. On the base of medical records, interviews and different self reported questionnaires (Mississippi Scale for combat-related PTSD, Mc Gill Pain Questionnaire, Pain Outcomes Questionnaire, Brief Pain Inventory, Beck Depression Inventory)the authors analysed the interrelationship between chronic pain and chronic PTSD, as well as different therapeutical approaches that were used in the treatment. Patients suffered from different chronic pain syndrommes (mostly low back pain and headaches). Afective component of pain were significantly correlated with the level of PTSD symptoms. Comorbid depressive symptomatology were correlated with higher pain scores. Patients were previously treated with different combination of analgesics and psychotropic drugs, usually prescribed by many different physicians, and multidisciplinary assessment and treatment of the patients at the Pain Clinic improved treatment outcomes with reduced costs. We assume that chronification of stress disorder has a similar pattern of genesis in relation to acute stress stimuli as well as chronic pain syndrome in relation to peripheric painful stimulus. In both cases hypersensitivity occurs changing patients' perception of the world and causing reaction to a non-noxious stimulus. Interrelationship between chronic pain and PTSD requires a multidisciplinary approach to the assessment and treatment of patients with the emphasis on rational polipharmacy and psychotherapeutical interventions.