Spa therapy is one of the most commonly used non-pharmacological approaches for many rheumatic diseases. In Fibromyalgia Syndrome (FS) it may be useful for the chronic widespread musculoskeletal pain. Because of the unknown aetiology and the not clear understood pathogenesis, there is no standard therapy regimen for FS. Also the mechanisms of action of spa therapy are not completely known, but most probably the benefits could be derived from mechanical, physical and chemical factors. Muscle tone and pain intensity can be positively influenced by mud packs and thermal baths. The review of international data from 2000 to 2007 confirms that spa therapy should be a valid tool in the multidisciplinary approach of the Primary FS.