OBJECTIVES: Obesity is on the rise globally, especially in developed countries and Australia is no exception. Currently, the most effective treatment for sustainable weight loss is bariatric surgery. This study is the first of its kind to assess the cost-effectiveness of 3 bariatric surgery procedures in comparison with standard care in Australia.   METHODS: A decision analytic model incorporating Markov process will be undertaken to compare adjustable gastric banding (AGB), Roux-en-Y Bypass (RYGB) and sleeve gastrectomy (SG) against standard care. The states will be based on BMI categories obtained from WHO and NICE guidelines. The cycle length will be one year and, owing to the limited availability of long-term data for bariatric procedures, the model will have a time horizon of 10 years. Utilities will be based on the SF-6D and transition probabilities will be derived from a network meta-analysis of BMI reductions as the treatment effect for the various comparators. Cost data will be obtained from the Australian Institute of Health and Welfare (AIHW). Construction of the model will be carried out via Microsoft Excel and the results will be presented as a comparison of costs and quality-adjusted-life years (QALYs) to generate ICERs for each of the interventions. One-way sensitivity analysis in addition to PSA will be carried out to test the robustness of the model in terms of the assumptions made and various input parameters. RESULTS: Construction of the model has already commenced and will be finished by mid-July; full completion of the write-up will be completed by the end of July. This research is carried out in conjunction between City University London and Griffiths University (Brisbane, Australia). CONCLUSIONS: To be completed by 15/07/2015.