OBJECTIVE: To characterize the burden of illness of fibromyalgia to employers, insurers, and society. METHODS: Two databases were searched, Medline and Healthstar, limited to English language and years 1990-2004. Key search words included fibromyalgia, cost, economics, employment, productivity and disability. Articles were selected that reported utilization of health care resources characterized by either indirect or direct costs. The total cost of fibromyalgia and contributing cost drivers were determined; costs were compared to other diseases. RESULTS: A total of 12 articles were reviewed for cost and five of these reported productivity cost. The estimated annual total cost per patient was $5,163-$11,548 for employers, $2,274 -$9,374 for insurers and $3,534.84 for society. Direct costs included: inpatient, outpatient, office visits, medications, alternative medicine, diagnostic tests, lab work and emergency room visits. Indirect costs included: absenteeism, presenteeism, work loss and disability. Productivity loss, medical care and prescriptions were the major determinants of costs to employers. Insurer costs were driven by inpatient care, medications and outpatient visits. Societal costs were driven by health care procedures and productivity impairments. Productivity costs were accountable for 26%-54% of the total cost to employers, and were most often measured by disability and time off work. Only one abstract was identified that measured productivity in FMS patients using a patient-reported measure. CONCLUSION: Fibromyalgia is a costly condition; with cost drivers varying by payor type. Productivity is a significant cost driver that should be considered to capture the full burden of fibromyalgia to both the employer and society. Most studies assessing productivity only addressed absenteeism ± disability without regards to presenteeism; true productivity costs are likely even higher than reported. Cost assessment measures in clinical trials for fibromyalgia need to be determined.