OBJECTIVES To estimate the economic burden of diabetes, hypercholesterolemia and hypertension related to overweight and obesity in Mexican children aged between five and eleven years during their life-time. METHODS A Discrete Event Model was designed to calculate prevalence and yearly incidence of diabetes, hypercholesterolemia and hypertension and its related costs during the life-time of a children cohort aged between five and eleven at the start of the simulation. The size of the cohort is one of one thousand of the total population reported by the Mexican Population Council for that age range. Data of risk of dying at each age was obtained from the same source and a 0.2% was added for each comorbidity. Costs were obtained from the Popular Insurance report of 2001. Due to the absence of data related to incidence of comorbidities in overweight and obese children, adult data was used but smoothed by an exponential curve. Probability of becoming overweight and obese was obtained from the National Health and Nutrition Survey of 2006. A 3% discount rate was used for all costs. Results are presented in US dollars with an exchange rate of 13.5 MXN pesos for 1 US dollar. RESULTS Total expenditure in comorbidities for children that became obese at any time during simulation was $96,632,485,372, for those who became overweight was $90,513,280,890 and for those that remain in normal weight was $55,650,160,294. CONCLUSIONS From the results of the model it can be said that for the group of children currently aged between 5 and 11 years an extra $ 41 billion will be spend in comorbidities of those that will become obese and an extra $ 35 billion for those that will become overweight compared to those that will remain in a normal weight.