Result: Of the 179 eligible patients, 103 were male and 76 were female. The median age was 70 years. The median whole tumor size, solid component size, and consolidation/tumor ratio on CT were 2.1 cm (range, 0.3-5.8 cm),1.7 cm (range, 0-3.0 cm),and 87% (range, 0-100%),respectively. The median SUV max on FDG-PET/CT was 4.20 (range, 0.78-28.07). According to the postoperative pathological examination, 147 patients (82%) had adenocarcinoma, 25 (14%) had squamous cell carcinoma, and 7 (4%) had other types of NSCLC. Pleural involvement, pulmonary metastasis, lymph node metastasis, lymphatic permeation, and vascular invasion were identified in 26 (15%), 6 (3%), 15 (8%), 11 (6%), and 19 patients (11%), respectively, and in total, 46 patients (26%) developed the pathological metastasis and/or involvement. The univariate analysis identified SUV max , sex, carcinoembryonic antigen, Sialyl Lewis x-1, whole tumor size, solid component size, consolidation/tumor ratio, diseased side, tumor location, and tumor histology as significant predictors. A multivariate analysis revealed SUV max (OR: 1.197, p<0.001) and consolidation/tumor ratio (OR: 1.052, p ¼ 0.001) as significant independent predictors. The solid component size and whole tumor size were not identified as significant independent predictors. By the ROC analysis, the optimal cutoff point for SUV max was determined as 6.10. Thirty-seven of the 67 patients (55%) with 6.10 of SUV max developed the pathological metastasis and/or involvement whereas 9 of the 112 patients (8%) with <6.10 of SUV max developed pathological metastasis and/or involvement. Conclusion: Our results suggested the predictive effect of high SUV max on pathological metastasis and involvement in clinical stage IA NSCLC patients. Thus, FDG-PET/CT should be utilized for the preoperative precise evaluation of early stage NSCLC, and we may consider SUV max on FDG-PET/CT to decide surgical procedure for these patients, such as the extent of pulmonary resection and lymphadenectomy.