The impact of stressful life events on the development and onset of chronicity of low-back pain is not yet fully understood. Sixty-four consecutive patients with chronic low-back pain treated at the orthopedic out-patient unit of the Innsbruck University Hospital were investigated with regard to stressful life events. Patients were classified into two groups: one group consisting of patients whose pain had an organic etiology (n= 16), and another group consisting of those with pain of uncertain origin (idiopathic group, n=48). A method combining a semistructured interview with a self-assessment of the severity of stress caused by life events was employed for assessing the impact of such events on chronic low-back pain. In comparison to the patient group having organic causes of pain, the idiopathic group showed significantly more patients having at least one highly stressful event preceding the last substantial aggravation of pain (p=0.028). The latter group experienced significantly more exhaustion (p=0.016) and significantly more difficulties in active coping (p=0.011) when confronted with stressful life events. Stressful life events that arouse feelings of helplessness may contribute to the development of chronic idiopathic low-back pain. Our results emphasize the importance of investigating the subjective meaning and appraisal of stressful life events, taking into consideration both individual predisposition and psychosocial resources available to the patient. Finally, it is also important that the attending physician be aware of any life event that is particularly stressful for the patient so that psychosocial help be made available at the appropriate time.