OBJECTIVES: To evaluate the most cost-effective strategy of staging non-small cell lung cancer with hybrid PET/CT to avoid unnecessary surgeries. METHODS: A decision tree model was developed with four work-up approaches: CT alone, PET/CT for all, PET/CT when negative CT, and CT plus PET/CT for all. Mediastinoscopy was included in all alternatives to confirm positive CT or PET/CT. Surgery was considered unnecessary when the work-up drives to resectable stage but the model predicts loco regional or distant metastasis. The model incorporated evidence-based data from the literature and associated costs were evaluated from the Brazilian public health care system perspective. The costs of PET/CT in Brazil were estimated in previous study by microcosts technique. The impact of uncertainties on the model was verified by deterministic and probabilistic sensitivity analyses (PSA). RESULTS: For each strategy, a simulation of 1000 individuals has shown the costs and effects (US$/ avoidable surgery) as follow: US$1.088.248,85/ 0; US$2.620.087,94/ 151; US$2.432.104,45/ 170 and US$2.740.718,99/ 181, respectively. The incremental cost-effectiveness ratio (ICER) per avoidable surgery was more favorable for PET/CT in negative CT (US$7.888/ surgery) than PET/CT for all (US$10.127/ surgery) and CT plus PET/CT (US$9.108/ surgery) versusCT alone. In sensitivity analysis, estimates of ICER were sensitive to changes in the probability of distant metastasis, the cost of PET/CT procedure and probability of N0/1 disease. CONCLUSIONS: Although PET/CT is recommended for staging potential resectable lung cancer patients, the procedure is not reimbursed in Brazilian public health care system yet. Our study shows that include PET/CT in the work-up staging of lung cancer could prevent misleading surgeries due to undiagnosed advanced disease. In term of cost-effectiveness, PET/CT in negative CT patients is the most cost-effective strategy with a probability higher than 90% when the willingness-to-pay is US$10.000,00 superior.