Objective To understand the risk factors for postoperative pneumonia in elderly patients with non-small cell lung cancer(NSCLC), and explore the preventive measures. Methods Clinical data of surgical patients aged>70 years and with NSCLC in a hospital from January 2016 to November 2018 were retrospectively analyzed, incidence of postoperative pneumonia, distribution of pathogens, and related risk factors were analyzed statistically. Results Among 398 lung cancer surgical patients, 36 had postoperative pneumonia, infection rate was 9.05%; 43 strains of pathogens were isolated, including 20 strains (46.51%) of gram-negative bacteria, 9 strains(20.93%) of gram-positive bacteria and 14 strains (32.56%) of fungi. Multivariate logistic regression analysis showed that age ≥ 75 years, chronic obstructive pulmonary disease (COPD), forced expiratory volume in one second (FEV₁)% <70, thoracotomy, lobectomy, duration of operation ≥ 180 minutes, serum albumin <35 g/L were independent risk factors for postoperative pneumonia (all P<0.05). Conclusion Incidence of postoperative pneumonia in elderly patients with NSCLC is high and with multiple influencing factors, corresponding preventive and control measures should be taken to reduce the incidence of postoperative pneumonia.