The fibromyalgia syndrome (FMs) is a non-articular rheumatic condition characterized by a variety of symptoms related to pain. Like many other clinical syndromes, FM has no single specific feature but represents a complex of symptoms of self reported or clinical deduction. Unfortunately, there is still no standardized laboratory test to detect FM or measure its severity. The aim of our work was to investigate various biological aspect of FM, trying to find biological markers useful to diagnosis and which could be used as a pharmacological target. In particular we analyzed the pheripharal Benzodiazepine receptor, the alteration of serotonin transporter, the concentration of Anti-polymer antibodies, the association between thyroid autoimmunity and FM severity, and the ATP, Magnesium and calcium levels in platelet of fibromyalgic patients. Moreover, we analyzed the psychiatric comorbidity of a cohort of FM subjects, to correlate the Quality of life of FM patients and the psychiatric illness.