Objective To reduce the incidence of hypoxemia in patients after general anesthesia in the post anesthesia care unit (PACU), and to enhance the quality and safety of anesthetic care. Methods A total of 1,028 patients undergoing elective surgery under general anesthesia were studied and their oxygen saturation values, basic information, intraoperative anesthesia and laboratory indicators were recorded. Risk factors for postoperative hypoxemia were determined by logistic regression analysis and a prediction model was identified. Results The prevalence of hypoxemia in the PACU was 21.79%.The age of 70 years or older, body mass index of 25 or more, American Society of Anesthesiologists Physical Status Classification (ASA) score ofⅡor greater, and thoracic surgery were risk factors for hypoxemia (P＜0.05 for all). Conclusion The prevalence of hypoxemia in the PACU is relatively high.Patients with advanced age, obesity, ASA score of Ⅱ or greater, and receiving thoracic surgery should be paid more attention.