Objective: To evaluate the effects of preoperative inspiratory muscle training (IMT) on the incidence of atelectasis in patients at high risk of postoperative pulmonary complications scheduled for elective total hip replacement surgery under general anesthesia. Methods: Thirty two high-risk patients undergoing elective total hip replacement surgery under general anesthesia were chosen from Nanjing Medical University, Affiliated Nanjing First Hospital. In this single-blind randomized controlled clinical trial, patients were randomly assigned to receive preoperative inspiratory muscle training or conventional treatment (CT). The major effectiveness outcome variables were atelectasis and duration of postoperative hospitalization. Results: Both groups were comparable prior to surgery. Seven patients in the CT group and 3 in the IMT group developed atelectasis (P = 0.25). Median duration of postoperative hospitalization was 13 days (range, 10～17 days) in the IMT group versus 16 days (range, 11～23 days) in the CT group (Mann-Whitney U statistics, Z = -2.22, P = 0.03). Mean postoperative inspiratory pressure was 5% higher in the IMT group. Conclusion: Preoperative intensive inspiratory muscle training appears to reduce the incidence of atelectasis and duration of postoperative hospitalization in patients at high risk of developing postoperative pulmonary complications who were scheduled for elective total hip replacement surgery under general anesthesia.