Objective?To investigate the incidence of perioperative complications of non-cardiac surgery in elderly patients under general anesthesia and analyze its risk factors. Methods?A total of 427?elderly patients undergoing non-cardiac surgery under general anesthesia were reviewed between January 2020?and December 2021?at Shanghai Songjiang District Central Hospital. Patients were divided into both of complication group (57?cases) and non-complication group (370?cases) based on whether postoperative complications were developed or not. Univariate and multivariate analyses were performed to identify risk factors for postoperative complications. Results?Postoperative complications occurred in 57?patients (13.35%). Compared with patients in non-complication group, those patients in complication group experienced longer duration of intraoperative hypotension. The rate of ICU admit, ICU stay and length of hospital stay were higher or longer. Multivariable logistic analysis identified increased operation time, preoperative renal dysfunction, ICU admit and longer ICU stay as risk factors of postoperative complications (P<0.05). Conclusion?Elderly patients undergoing non-cardiac surgery under general anesthesia have a higher incidence of perioperative complications. Preoperative renal insufficiency, prolonged operation， ICU admit and longer ICU stay are independent risk factors for increased postoperative complications, which should be paid attention in clinical work.