OBJECTIVES: The prevalence of COPD in Brazil is estimated in 15,8% and it is the fourth cause of hospitalization a in the Brazilian public health system (SUS) in the last 10 years. Until recently only the short-action and long-action β2-agonists were distributed to COPD patients by SUS. The aim of this study was to determine the expected consequences on the cost and effectiveness and the budgetary impact of the recent introduction in SUS of budesonide and beclomethasone for the treatment of COPD patients. METHODS: Systematic review of the literature and development of a decision analytic model to demonstrate the immediate response to treatment with inhaled steroids and project the results in terms of effectiveness and cost based on current knowledge of the natural history of the disease. The analysis was performed for a hypothetical cohort of adults with forty or more years with COPD GOLD stage II, III or IV. The primary perspective of the study was SUS. Data sources were the medical literature, official published prices of SUS for medicines and DATASUS (SUS database). RESULTS: Corroborating the results of other systematic reviews we also did not detect differences in efficacy and safety between budesonide and beclomethasone therefore we performed a cost-minimization analysis. Both steroids reduced the exacerbation rate in about 40%. The annual costs of the treatment with budesonide and beclomethasone were 714,29 and 786,77, respectively. The parameter that led to greater variation in the model was the cost of hospitalizations with ICU stays. The projected budget impact for introduction of inhaled corticoids (50%/50%) for COPD treatment in 2013 is about R$345 million reais. CONCLUSIONS: There are no differences in efficacy and safety between the studied inhaled steroids. To achieve about 40% reduction in the exacerbation rate the budget impact for SUS in 2013 would be of approximately R$345 million reais.