Postoperative pulmonary complications (PPCs) significantly impact surgical outcome. We investigated the predictive ability of controlling nutritional status (conUt) for ppc after lung resection in patients with non-small cell lung cancer (NSCLC). We retrospectively reviewed data of 922 patients with NSCLC who underwent complete resection from January 2016-December 2017. We analyzed the frequency and characteristics of ppcs and compared receiver operating characteristic (Roc) curves of various prognostic models to predict PPCs. A CONUT score higher than 1 was considered as a high CONUT score. Total incidence of PPCs was 8.6% (n = 79). The proportion of pneumonia was significantly larger in the high conUt group (P < 0.05). The CONUT consistently had a higher area under curve (AUC) value (0.64) than other prognostic models (prognostic nutritional index (PNI): AUC = 0.61, Glasgow prognostic score (GPS): AUC = 0.57, and assessment of respiratory risk in surgical patients in Catalonia (ARISCAT): AUC = 0.54). Multivariate analysis identified underweight [Odds ratio (OR) = 4.57, P = 0.002] and high CONUT score (OR = 1.91, P = 0.009) as independent PPCs prognostic factors. One-year mortality rate for high CONUT score was significantly higher (hazard ratio = 7.97; 95% confidence interval, 1.78-35.59). Preoperative CONUT score is an independent predictor of PPCs and 1-year mortality in patients with resectable NSCLC. Postoperative complication (PPC) is critically important for patient outcomes, and is associated with mortality, morbidity, and length of stay in both thoracic and non-thoracic surgical patients 1. Although the definition of PPCs varies in the literature, it generally includes prolonged air leak, pneumothorax, atelectasis, pleural effusion, respiratory infections, broncho-pleural fistula, and acute respiratory distress syndrome (ARDS) 2. In patients undergoing thoracic surgery in particular, the incidence of PPCs is reported to be between 3 and 49%, with mortality ranges ranging 2-12% 3. Therefore, careful preoperative evaluation is needed to predict PPCs, and this is a common concern among thoracic surgeons, pulmonologists, and anesthesiologists. Various PPCs prediction models have been previously developed; these include the assessment of respiratory risk in surgical patients in Catalonia (ARISCAT) model, Gupta risk calculators, and the respiratory failure risk index suggested by Arozullah et al. 2,4-6. However, these models require diverse preoperative parameters, which bring questionable clinical usefulness of those. Moreover, detailed nutritional status is not reflected in any of these models.