Objective To investigate the current status of constipation during postoperative hospitalization and the factors associated with moderate to severe constipation at discharge in lung cancer patients. Methods Lung cancer patients who underwent surgery in 6 tertiary hospitals in Sichuan Province from November 2017 to January 2020 were enrolled. The MD Anderson Symptom Scale-Lung Cancer Module was used to collect postoperative constipation scores. Unconditional logistic stepwise regression was used to analyze the related influencing factors for moderate to severe constipation on the day of discharge. Results Finally 337 patients were collected. There were 171 males and 166 females, with an average age of 55.0±10.3 years. Constipation scores of lung cancer patients increased from postoperative day 1 to day 3, and showed a decreasing trend from day 3 to day 7. Moderate to severe constipation was present in 68 (20.2%) patients at discharge. The postoperative hospital stay (OR=0.743, P<0.001) and the dose of morphine used during postoperative hospitalization (OR=1.002, P=0.015) were influencing factors for moderate to severe constipation at discharge in lung cancer patients. ConclusionLung cancer patients have the most severe constipation on postoperative day 3. Moderate to severe constipation at discharge is associated with the postoperative hospital stay and the dose of morphine used during postoperative hospitalization.