PURPOSE: The incidence of lung cancer has increased steadily. We meta-analyzed to assess the impact of 18F-FDG PET on the management of lung cancer to detect recurrence/metastasis. MATERIALS AND METHODS: We performed systematic searches of Medline and Embase databases for English-language publications. All published studies regarding the impact of PET on the management of patients with lung cancer in detection of recurrence/metastasis were searched. The proportion of management change (%) defined as the percentage of patients who changed management after FDG PET to patients who had FDG PET was calculated. The data from each study were analyzed using MedCalc Statistical Software version 14.12.0 (MedCalc Software, Ostend, Belgium). RESULTS: Eight studies including 523 patients were eligible for inclusion in the study. The impact of 18F-FDG PET for the purpose of detecting recurrence/metastasis in patients with lung cancer was evaluated using management change rates, which were ranged from 28.6% to 79.2% with a pooled effect of 61.4% (95% confidence interval, 49.5%-72.7%; I2 = 85.7%). In a subgroup analysis, impact of 18F-FDG PET was evaluated in studies of patients with non-small cell lung cancer with indication of abnormal findings of conventional imaging, elevated tumor markers, and clinical symptoms with the pooled rate of management change of 62.2% (95% confidence interval, 44.2%-78.5%; I2 = 88.0%). CONCLUSIONS: We have highlighted that 18F-FDG PET has a major impact on the management of patients with recurrent lung cancer. These findings suggest that 18F-FDG PET should be performed in patients with lung cancer, especially in cases involving equivocal or suspicious recurrence/metastasis on conventional imaging, elevated tumor markers, or clinical symptoms during follow-up.