18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) for lung cancer may be a biomarker for malignancy as well as a useful tool for detection of nodal involvement and distant metastasis. The goal of this study was to clarify a relationship between clinicopathological findings and maximum standardized uptake value( SUVmax) obtained by preoperative PET in patients with non-small cell lung cancer in diameter of 2 cm or less. Between January 2008 and April 2011, 124 patients( 54 men and 70 women) with non-small cell lung cancer in diameter of 2 cm or less undergoing lobectomy or segmentectomy were enrolled. The relationship between SUVmax and clinicopathological findings as tumor diameter, histological type, pleural invasion, vascular invasion, lymphatic permeation and nodal involvement were analyzed. Correlation between SUVmax and findings such as vascular invasion and lymphatic permeation showed relatively strong in the patients with adenocarcinoma, on the contrary to the correlation in the patients with non-adenocarcinoma. No tumor showing SUVmax of 2 or less showed vascular invasion and/or lymphatic permeation as well as nodal involvement in any patients with adenocarcinoma. SUVmax of the primary tumor in diameter of 2 cm or less, can be a useful biomarker which indicates a surgical candidate for sublobar pulmonary resection as well as mediastinal nodal dissection, especially in patients with adenocarcinoma.