Objective To analyze the risk factors associated with prolonged length of hospital stay (PLOS) after lobectomy for lung cancer patients. Methods The clinical records of 771 lung cancer patients undergoing lobectomy between May 2012 and June 2016 in the Second Affiliated Hospital of Harbin Medical University were retrospectively analyzed. According to different length of hospital stay (LOS), 771 patients were divided into two groups, a normal LOS group and a PLOS group. In the normal LOS group, there were 551 patients including 234 females and 317 males with a median age of 59 years, whose LOS was shorter than 8.0 days. In the PLOS group, there were 220 patients including 72 females and 148 males with a median age of 60 years, whose LOS was no less than 8.0 days. Then, we analyzed the independent risk factors of PLOS by multivariate logistic regression analysis. Results Univariate analysis showed that risk factors for PLOS included male, arrhythmias and atrioventricular block, smaller FVC%, unilateral pneumonectomy, operation and anesthesia duration, intraoperative blood loss and number of lymph node dissection in the operation (P<0.05). Multivariate logistic regression analysis showed that the age ≥75 years (OR=4.100, 95%CI 1.677 to 10.026), unilateral pneumonectomy (OR=2.563, 95%CI 1.473 to 4.460), FVC% < 89.05% (OR=1.500, 95%CI 1.020 to 2.206), numbers of lymph node dissection≥ 13.5 (OR=1.826, 95%CI 1.262 to 2.642), operation duration≥126.5 min (OR=1.858, 95%CI 1.200 to 2.876) and arrhythmia (OR=2.944, 95%CI 1.380 to 6.284) were independent risk factors of PLOS (all P<0.05). Conclusion LOS is influenced by age, surgical type, FVC%, numbers of lymph node dissection, arrhythmia and operation duration. Careful assessment and appropriate management of risk factors are helpful to improve postoperative recovery after lobectomy for lung cancer patients.