CONTEXT Recent studies have demonstrated the potential cost-effectiveness of using 2-fluoro-2-D-[(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the management of non-small cell lung carcinoma (NSCLC), but because of differences in health-care systems, those findings may not hold true in a Japanese hospital. OBJECTIVE To assess the cost-effectiveness of the chest CT plus chest FDG-PET strategy in Japan. DESIGN Decision-tree sensitivity analysis based on the two competing strategies of chest CT-alone vs chest CT plus chest FDG-PET. STUDY SELECTION A simulation of 1,000 patients in whom NSCLC, stage IIIB or less, was suspected was created using baselines of other relevant variables in regard to sensitivity, specificity, mortality, life expectancy, and cost from published data. METHODS We surveyed the relevant literature for the choice of variables. MAIN OUTCOME MEASURES Expected marginal cost and expected life expectancy gain for NSCLC patients. RESULTS The chest CT plus chest FDG-PET strategy yielded an expected life expectancy gain of 0.607 years (7.3 months) per patient, compared with the alternative strategy of chest CT-alone. Using an FDG-PET examination cost of 1.0 x 10(5) yen (around $700 US) per study, the cost increment was 2.18 x 10(5) yen/yr/patient. CONCLUSIONS The chest CT plus chest FDG-PET strategy in patients with NSCLC is unlikely to be cost-effective in Japan. However, patient life expectancy gain would increase as a result of improved staging of NSCLC. These preliminary results should be confirmed by further studies for specific environments.