Fibromyalgia is often understood as a syndrome mainly characterised by widespread pain and tenderness and "unexplained" etiology and pathogenesis. In the last years evidence is growing that biological as well as psychosocial stress play a pathogenetic key-role. Beginning with the general function and development of the stress response system the actual knowledge of its relationship with central pain-processing mechanisms is reviewed. Early adverse childhood experiences can impair the function of the stress system all over the lifespan. Subsequently, research evidence for the role of stress in the etiopathogenesis of fibromyalgia is summarised. Psychological as well as psychobiological consequences are outlined. Finally, an integrative model of fibromyalgia is proposed, which may put several pieces of a biopsychosocial puzzle together. This model offers an approach for the differentiation of subgroups and a clinical orientation for developing an adequate therapy for the individual patient.