Characterized by chronic widespread joint and muscle pain, fibromyalgia is a syndrome of unknown etiology. The American College of Rheumatology's classification criteria for fibromyalgia include diffuse soft tissue pain of at least 3 months' duration and pain on palpation in at least 11 of 18 paired tender points. Symptoms are often exacerbated by exertion, stress, lack of sleep, and weather changes. Fibromyalgia is primarily a diagnosis of exclusion, established only after other causes of joint or muscle pain are ruled out. The initial workup for patients who present with widespread musculoskeletal pain should include a complete blood count, erythrocyte sedimentation rate, liver function tests, hepatitis C antibody, calcium, and thyrotropin. The musculoskeletal system, the neuroendocrine system, and the central nervous system, particularly the limbic system, appear to play major roles in the pathogenesis of fibromyalgia. The goal in treating fibromyalgia is to decrease pain and to increase function without promoting polypharmacy. Brief interdisciplinary programs have been shown to improve subjective pain. Fibromyalgia is a complex syndrome associated with significant impairment on quality of life and function and substantial financial costs. Once the diagnosis is made, providers should aim to increase patients' function and minimize pain. This can be accomplished through nonpharmacological ahd pharmacological interventions. With proper management, the rate of disability appears to be significantly reduced.