No standardized postoperative follow-up strategy has been established for lung cancer patients, although CT and tumor markers are often employed. We conducted a retrospective study evaluating fluoro-2-deoxyglucose positron emission tomography (FDG-PET) for the diagnosis of postoperative recurrence of lung cancer. We evaluated 28 patients with suspected postoperative recurrence of lung cancer, who underwent FDG-PET between July 2004 and November 2005. Of these, 15 showed positive PET finings. Recurrence of lung cancer cases confirmed in 14 of these and the remaining case showed a postoperative scar. Thirteen patients with no findings on PET scan have demonstrated no evidence of recurrence during follow-up periods between 10 to 23 months. The negative predictive value was therefore 100%. FDG-PET in addition to chest CT and tumor markers for the diagnosis of the postoperative recurrence of lung cancer is considered to be beneficial in terms of avoiding excessive radiation exposure and limiting medical costs, but further evaluation in more patients is necessary.