목적: The aim of this study was to investigate the effect of oropharyngeal obstructive sleep apnea (OSA) surgery on the objective outcomes such as success rate and apnea-hypopnea index (AHI) and compare success rate and AHI reduction according to the anatomical factors including tonsil size and palate-tongue position. 방법:A total of 156 consecutive OSAS adult patients (M = 149, F = 7 / mean age SD = 38.9 9.6) who underwent oropharyngeal surgery (e.g., uvulopalatopharyngoplasty UPPP, uvulopalatal flap UPF, and tonsillectomy) were enrolled. The objective surgical outcomes were evaluated according to the anatomical factors such as tonsil size (big or small tonsil) and palate- tongue position (low- or high-level tongue). Surgical success was defined as a reduction of at least 50% in preoperative AHI and a postoperative AHI of less than 20. AHI reduction (%) was defined as (postoperative AHI preoperative AHI) x 100 / postoperative AHI. 결과:The patients were divided into 4 groups (Group 1, big tonsil and low-level tongue / Group 2, big tonsil and high-level tongue / Group 3, small tonsil and low-level tongue / Group 4, small tonsil and high-level tongue). The overall success rate was 55.8% (87/156) and surgical success rates in Group 1, 2, 3, and 4 were 83.0% (39/47), 60.9% (14/23), 47.6% (20/42), and 31.8% (14/44), respectively. The overall AHI reduction was 53.5% and AHI reductions in Group 1, 2, 3, and 4 were 74.1%, 71.2%, 34.4%, and 30.4%, respectively. 결론:The prediction of objective outcomes including AHI reduction before oropharyngeal OSA surgery may be possible according to the anatomical factors including tonsil size and palate-tongue position.