OBJECTIVES The costs of obesity are staggering, accounting for 2-6% of global health care costs. The health economic benefits of bariatric surgery while notable, are multi-faceted, resulting in heterogeneous reporting in the literature. To that end, this study seeks to 1) highlight available evidence of the health economic impact of bariatric surgery, and to 2) identify key gaps in current evidence that may influence uptake by healthcare systems. METHODS Evidence of the health economic impact was collated from 107 scientific articles, of which 19 were systematic reviews, published between 2010-March 2014 and archived in MEDLINE and PubMed. Additionally, HTAWatch identified 10 HTAs, largely from North America and the EU that evaluated economic benefits. RESULTS In all countries where evaluated, bariatric surgery was cost-effective compared to non-surgical therapy. The surgery was likely more cost-effective with higher patient BMI and with comorbidities, especially for BMI> 40kg/m, although estimates varied. Furthermore, resolution of underlying comorbidities resulted in reduced utilization of healthcare services, pharmaceutical utilization, and improved work productivity, among others, resulting in cost saving of 60-70% relative to standard care over a 3-year period. Importantly, time to break even was typically in the 4-7 years range, and was shorter for patients with Type 2 Diabetes Mellitus (T2DM) and with BMI>40kg/m, typically in the 1.25-5 year range. Three key evidence gaps were identified: few studies computed long-term cost-effectiveness; no head-to-head trials have directly compared different surgical procedures; and heterogeneity across populations and health system impede meta-analyses of patient outcomes such as QoL and long-term health benefits.  CONCLUSIONS Although heterogeneous, reports of health economic benefits of bariatric surgery indicate an overall positive trend, largely via reduction of health resource utilization. To firmly establish its impact, future studies need to conduct head-to-head comparisons, determine optimal patient populations, and employ standard clinical endpoints to demonstrate real world, long-term benefits.