['The aim of this study was to investigate the smoking status of lung cancer patients and to confirm the risk of smoking for patients undergoing lung cancer surgery.', 'We conducted a retrospective study of patients undergoing lung cancer surgery. Between May 2004 and March 2013, 716 patients underwent lung cancer surgery at our institution. Based on smoking status, the patients were classified into 3 groups: nonsmoker, past smoker, and current smoker. Based on exclusion criteria, a final total of 670 patients were investigated for the association between smoking status and postoperative complications. In addition, we explored the effect of smoking on survival after surgery.', 'There were 254 non-smokers, 246 past smokers, and 170 current smokers. The percent of female patients, adenocarcinoma, and stage IA cancer was highest in the nonsmokers. Respiratory function was significantly impaired in past and current smokers. Respiratory and cardiac complications were found less frequently in non-smokers (11.4%) followed by 17.1% of past smokers and 21.2% of current smokers (p = 0.0226). Univariate analysis showed that smoking was a significantly poor prognostic factor for overall survival. The 5-year survival rates for non-smokers, past, and current smokers were 81.4, 65.4, and 68.8%, respectively (p = 0.0003).'] Is smoking a perioperative risk factor and prognostic factor for lung cancer surgery?