PURPOSE: In totally endoscopic off-pump left atrial appendage (LAA) closure and surgical ablation, securing the operative field is sometimes difficult in some patients because of a narrow working space caused by an elevated diaphragm or ventricles. In this study, we aimed to investigate the effectiveness of a method that facilitates securing the operative field using an artificial Pneumothorax. METHODS: We analyzed 71 consecutive patients who underwent totally endoscopic off-pump LAA closure and bilateral pulmonary vein isolation. The factors contributing to the reduction in operative time were examined. The patients were divided into the following 2 groups according to whether or not an artificial Pneumothorax was used: Group C comprised 24 patients without an artificial Pneumothorax and Group A comprised 47 patients with an artificial Pneumothorax. RESULTS: There were no hospital deaths or major complications. The operative time was significantly shorter in Group A (108 �� 26 minutes) than in Group C (198 �� 77 minutes) (p <0.0001). CONCLUSIONS: In totally endoscopic off-pump LAA closure and surgical ablation, an artificial Pneumothorax may be useful in reducing the operative time.