ABSTRACT: BACKGROUND: Self-management education programs can reduce the complications and mortality in type 2 diabetes. The need to structure these programs for outpatient and community care with a vision for long-term maintenance has been recognised. In Reunion Island, an area affected by epidemiological and nutritional transition, diabetes affects 18% of the adult population over 30 years, with major social disparities, poor glycaemic control and frequent cardiovascular complications. Methods/design ERMIES is a randomised controlled trial designed to test the efficacy of a long-term (2 years) structured group self management educational intervention in improving blood glucose in non-recent, insufficiently controlled diabetes. After an initial structured educational cycle carried out blind for the intervention arm, patients will be randomized in two parallel group arms of 120 subjects: structured on-going group with educational intervention maintained over two years, versus only initial education. Education sessions are organised through a regional diabetes management network, and performed by trained registered nurses at close quarters. The educational approach is theoretically based (socio-constructivism, social contextualisation, empowerment, action planning) and reproducible, thanks to curricula and handouts for educators and learners. The subjects will be recruited from five hospital outpatient settings all over Reunion Island. The main eligibility criteria include: age [greater than or equal to]18 years, type 2 diabetes treated for more than one year, HbA1c [greater than or equal to] 7.5% for [greater than or equal to]3 months, without any severe evolving complication (ischaemic or proliferative retinopathy, severe renal insufficiency, coronaropathy or evolving foot lesion), and absence of any major physical or cognitive handicap. The primary outcome measure is HbA1c evolution between inclusion and 2 years. The secondary outcome measures include anthropometric indicators, blood pressure, lipids, antidiabetic medications, level of physical activity, food ingestion, quality of life, social support, anxiety, depression levels and self-efficacy. An associated nested qualitative study will be conducted with 30 to 40 subjects in order to analyse the learning and adaptation processes during the education cycles, and throughout the study. CONCLUSION: This research will help to address the necessary but difficult issue of structuring therapeutic education in type 2 diabetes based on: efficacy and potential interest of organising on-going empowerment group sessions at close quarters over the long term, in a heterogeneous socioeconomic environment. Trial registration: ID_RCB number : 2011-A00046-35 Clinicaltrials.gov number: NCT01425866.