Feng Jin,1,2 Anqin Han,2 Fang Shi,2 Li Kong,2 Jinming Yu2 1School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, 2Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Sciences, Jinan, People’s Republic of China Purpose: Although numerous studies have demonstrated associations between the preoperative neutrophil-to-lymphocyte ratio (NLR) and long-term outcomes in patients with non-small cell lung cancer (NSCLC), the prognostic significance of postoperative NLR and change in NLR (ΔNLR) is unknown for patients who underwent complete resection of stage I NSCLC. The aim of this retrospective study was to evaluate the prognostic significance of postoperative NLR and ΔNLR in 123 patients with stage I NSCLC. Patients and methods: This retrospective study included preoperative and postoperative data of 123 patients who underwent surgical resection for stage I NSCLC. The relationship between disease-free survival (DFS), overall survival (OS), and clinicopathological factors, including NLR, lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio, and their changes, was analyzed using both univariate Kaplan–Meier and multivariate Cox regression methods. Results: The 5-year DFS and OS rates in our cohort were 60.16% and 67.48%, respectively. Univariate analysis revealed that age (P=0.045), smoking status (P=0.033), preoperative NLR (P=0.032), postoperative NLR (P