BACKGROUND: For diabetic patients with lung cancer, blood glucose levels and medications such as metformin and statins may influence survival. OBJECTIVES: This study aimed to determine prognostic survival factors for diabetic patients with resected non-small cell lung cancer. PATIENTS AND METHODS: Between January 2005 and December 2013, 301 patients with type 2 diabetes mellitus who underwent curative resection for non-small cell lung cancer were identified and reviewed retrospectively. RESULTS: The median follow-up period was 48 months. In multivariate analysis for lung cancer-specific survival, older age, forced expiratory volume in 1 s (FEV1) <80% predicted, and advanced pathologic stage were significant negative prognostic factors; statin use was a positive prognostic factor (hazard ratio (HR), 0.468). In multivariate analysis for overall survival, male sex, older age, comorbidity index, and advanced pathologic stage were significant negative prognostic factors and proper glycemic control (HR, 0.621) and statin use (HR, 0.585) were positive prognostic factors. CONCLUSIONS: Proper glycemic control (glycated hemoglobin A1c <7%) is recommended for diabetic patients undergoing lung cancer operations. Further studies are required to elucidate associations between type 2 diabetes mellitus and antineoplastic effects of statins and to evaluate statins as a novel adjuvant treatment for lung cancer.