OBJECTIVE: To assess the efficacy of Cellfood's therapy in the treatment of fibromyalgia. METHODS: This study was a single-blind, cross-over, randomized placebo-controlled trial. Forty female were selected from 320 cases investigated in the period 2003-2005 of June. To be included in this study, it was required that the diagnosis of fibromyalgia was made by a specialist in according to the ACR classification criteria of 1990. The patient's age was between 35-47 years, the choice of criteria were the absence of improvements with the conventional therapy and the normality of medical check-up. The patients were divided into two different-groups of thirty-one and nine subjects, each-one (group A) treated with Cellfood for six months in according to the Eurodream's scheme, and each-other (group B) treated with placebo for three months and successively with Cellfood for three months. Besides we have estimated the tender points with algometer and the health status of women with the Fibromyalgia Impact Questionnaire (FIQ) at the baseline (T0) and at three (T1) and six month (T2). RESULT: The group A had an appreciable improvement of the parameters at T1 statistically significant compared to the group B, while we observed a stability of they at T2 on the group A and an improvement of the parameters of the group B statistically non significant compared to each-one. CONCLUSION: Our result suggest that the Cellfood's therapy improve fibromyalgia symptoms and health-related quality of life.