OBJECTIVES: to develop cost-effectiveness analysis of levofloxacin 750mg for 5 days (L750) versus levofloxacin 500mg for 10 days (L500) in hospitalized adults fine-risk class III/IV comunity-acquired pneumonia, under the Brazilian public payer perspective. METHODS: A literature search was conducted to gather efficacy data for L750 and L500 and identified one randomized controlled trial that showed L750-course for 5 days that achieved comparable clinical and microbiologic efficacy to the L500-course for 10 days. By day 3 of therapy, a greater proportion of patients in the L750 group had objective and subjective resolution of fever. The model assumed that L500 is the current practice in Brazilian public hospitals and patients are discharged at the time their course finishes. Resource use was estimated through expert panel. Only direct costs were included in the analysis and units were obtained from Brazilian official price lists. Number of hospitalized patients under the CID-10 code were obtained from the Brazilian official public health database(TABWIN). RESULTS: CONCLUSIONS: Short-course antibiotic therapy may provide new means to reduce healthcare costs. For more severe ill population, hospitalization and more agressive antimicrobial therapy may be necessary to achieve optimal clinical and economic outcomes. Besides, further studies about medication waste and its impact for the environment should be considered to be conducted.