OBJECTIVES: To assess the estimated prevalence of possible fibromyalgia (FM) sufferers among the adult population in Italy using a screening questionnaire, the London Fibromyalgia Epidemiology Study – Screening Questionnaire (LFESSQ). METHODS: Every patients going to visit a rheumatologist at a hospital in Firenze, during a 30-day period, what the reason of their visit, were interviewed using the LFESSQ with two additional questions on fatigue, and examined to confirm or exclude the diagnostic of FM using American College of Rheumatology (ACR) classification criteria. The screening questionnaire was also administered to a representative community sample more than 15 years old, selected by the quota method. The prevalence of FM was estimated in the general population, applying the predictive positive value, observed in consultation, to the positive screens, RESULTS: 31.3 % patients interviewed were found positive for chronic widespread pain, 20.7% for widespread pain and fatigue and in 26.2%[25.6-26.7] the diagnosis of FM was confirmed. In the general adult population, 10.1% subject were positive for widespread pain and 5.2% for widespread pain and fatigue. The prevalence in general population, is 6.6 % [5.1 – 8.1], if patients screened positive for chronic widespread pain are considered. If fatigue is added, the prevalence of 3.7 % [2.6 – 4.8]. Prevalence rises with age until the age group 75-84 years old. FM sufferers are 84% females and an average age of 52.9 years old (SD: 14.2). CONCLUSIONS: Our study confirms the results from Canada, US or Spain, with slight differences probably due to the different methodologies and populations employed. The minimum prevalence estimated of 3.6% in Italy, these means that approximately 1.8 millions of Italians, largely women, may suffer from FM.