OBJECTIVES: This study address the policy question of what is the actual economic burden of obesity in Chile and its projections until the year 2030. The aim of such research question is to inform decision-makers on the magnitude and potential future trends if no actions are undertake. METHODS: A transition state population level simulation model that incorporate the natural history of obesity and 16 related conditions had been development for the 2010-2030 period. Outcomes of the model consider annual number of cases, deaths, year of life lost (YLL) and direct cost associated with each condition. Epidemiological input data has estimated using DISMOD II® equations. Cost parameters are based on national representative data sources. Univariate and multivariate deterministic sensitivity analysis and second order Monte Carlo simulation for multivariate probabilistic analysis are performed. The model is programed in Excel (Microsoft ® Office Excel 15) with Visual Basic ® Macros. RESULTS: An average of 2,2% (CI95% 1,6%-2,9%) of the annual total health expenditure are attributed to obesity and its related conditions with a clearly increasing trend during the years of analysis, accounting for nearly 4% of the health expenditures in the year 2030. Both health and economic impact are greater in females than in males. Main drivers of those cost are gallstone disease, chronic kidney disease, bariatric surgery and type 2 diabetes mellitus that together contribute with more than 75% the health expenditures attributable to obesity within the country. CONCLUSIONS: Obesity represent a preventable condition that accounts for an important share of the total health expenditure of the Chilean health system. Increasing trends on the obesity prevalence and ageing are both important drivers of an expected future rise in the cost attributable to obesity in the country. Future works needs to address the potential impact of policy strategies to tackle this health problem.