Inclusion Criteria:

• Patients must meet the American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia
• Patients must have had widespread pain (pain in three quadrants and in the axial skeleton) for at least three months
• Patients must have pain on digital palpation in 11 or more of the 18 tender-point sites

Exclusion Criteria:

• Patients who previously failed tramadol HCl therapy or those who discontinued tramadol HCl due to adverse events
• Patients who have any of the following: active connective tissue or musculo-skeletal diseases (e.g., SLE or RA). Non-active SLE or RA patients will be permitted to enter the study. painful, symptomatic osteoarthritis which requires treatment with pain medication. Regional periarticular pain syndromes, spondyloarthropathy and major endocrine disease
• Patients who currently have more severe pain than the pain of fibromyalgia
• Patients who have taken antidepressants, cyclobenzaprine or anti-epileptic drugs for pain within three weeks of the Treatment Phase
• Patients who have taken short-acting analgesics, topical medications and anesthetics and/or muscle relaxants for a period of less than 21 days of the given medication prior to the Treatment Phase
• Patients who have started to use nutriceuticals (e.g. glucosamine) within four weeks prior to the Treatment Phase
• Patients who have received tender-point injections of local anesthetics within the last two months
• Patients with a significant major psychiatric disorder (e.g. major depression) or subjects receiving anti-psychotic medication
• Patients with a history of estimated creatinine clearance of < 30 mL/min
• Patients receiving acupuncture within three weeks prior to the Treatment Phase
• Patients who have epilepsy