Fibromyalgia (FM) is a chronic widespread pain and fatigue syndrome that affects 3 to 6 million adults in the United States. Consequences of FM include physical and psychological distress, loss of work productivity, reduced quality of life, and increased use of health resources. Although the mechanisms underlying the symptomatology of FM are not clear; one theory suggests potential alterations in cytokine balance. Because the symptoms of FM may be worsened by stress and negative psychological processes, mind-body modalities may positively influence the neuroendocrine and immunological mediators of symptoms in FM. Given that immune modulation by both psychosocial stressors and interventions has been linked to health changes, self-efficacy (i.e., the belief that one can cope), may be one mechanism affecting FM outcomes. The specific aims of this project are: (1) to test the effects of a 10-week guided imagery intervention in comparison to an attention control group among women diagnosed with fibromyalgia on (a) the primary outcomes of self-efficacy for managing symptoms and perceived stress and (b) the secondary outcomes of symptoms of fatigue, pain, distressed mood, and depressive symptoms and markers of immune function; and (2) to examine the relationships among self-efficacy for managing symptoms, perceived stress, symptoms of fatigue, pain, distressed mood, and depressive symptoms and markers of immune function. The biobehavioral framework to guide this project is adapted from psychoneuroimmunology. Using a randomized controlled two-group design with repeated measures, 72 individuals will be recruited and randomized into one of two groups: Usual Care plus guided imagery (GI) intervention (Group 1) or Usual Care alone (i.e., attention control group) (Group 2). The intervention consists of three 30-minute guided imagery audio recordings to be used in a proscribed manner over a 10-week period. An ANCOVA model will be used to test for group differences between the intervention and standard care groups at week 10. This project will be the first known to explore the relationships among cytokines and perceived stress and the symptoms of fatigue, pain and mood following the administration of a biobehavioral intervention in women with FM.