Background. Most fibromyalgia patients are seen in primary care (PC). However, the effectiveness of the treatments prescribed by general practitioners is usually minimal. The main objective of the present research is to assess the efficacy of structured psycho-educational intervention, combined with relaxation, developed to improve the quality of life of patients suffering fibromyalgia (FM). The second objective is to assess the cost-effectiveness of this multimodal intervention. Method/Design. Design. Randomized controlled trial with a 12-month follow-up involving two groups, one of which is the intervention group that includes patients receiving a psychoeducational program and the other the control group consisting of patients treated for FM in the usual way. Setting. Three urban PC centers in the province of Barcelona (Spain). Sample. The total sample comprises 218 patients (over 18 years of age) suffering FM, selected from a database (Rheumatology service-Viladecans Hospital) of patients with this illness. Only those patients introduced in the database between the years 2005 and 2007 were included in the selection. Selected patients will be asked for written informed consent to participate in the study. Intervention. Multi-component program including information about the illness, counselling about physical exercise and training in autogenic relaxation. The intervention consists of nine 2-hour sessions delivered during a two-month period. The pharmacological treatment prescribed by the physician was maintained in both groups. Main variables. Sociodemographic characteristics, quality of life, use and cost of healthcare and social services. Measures. Quality of life is to be measured with the FIQ and the EuroQol-5D, and the use of healthcare services with an adapted version of the Client Service Receipt Inventory (CSRI). These variables will be measured before the beginning of the program (baseline) and 1, 2, 6 and 12 months later. Discussion. This research project is an attempt to demonstrate that a psycho-educational program implemented in the context of PC can produce a significant increase in the quality of life for patients with FM, as well as a decrease in the use of healthcare and social services, compared with usual care. Trial registration. NCT00550966.