It is uncertain which factors substantially influence outcomes after uvulopalatopharyngoplasty (UPPP) in patients with supine predominant obstructive sleep apnea (POSA).To explore the predictors of UPPP outcomes in POSA patients.A total of 108 patient(52 positional patients (POSA) and 56 nonpositional patients(NPP)), who underwent the revised uvulopalatopharyngoplasty (H-UPPP), were retrospectively studied. The pre-operative information of these patients, including polysomnography (PSG), and upper airway CT, were collected for analysis.No difference was found in surgical success rates between POSA and NPP undergoing H-UPPP. In POSA patients, there were statistically significant differences between responders and nonresponders in body mass index (BMI), preoperative supine AHI, time of SaO2 < 90% (TS90) (all p < .05), minimal anteroposterior airway (mAP) (p = .016), minimal lateral airway (mLAT) (p = .002), minimal cross-sectional airway area (mCSA) (p < .001) at the velopharynx. mLAT (p = .014) and mCSA (p = .002) at the glossopharynx. The independent associated factors for surgical success were lower BMI (p < .001), narrowerm LAT (p = .002) and mAP (p < .001) at velopharynx, and wider mCSA (p < .001) at glossopharynx in POSA.POSA patients with lower BMI, narrower mLAT and mAP at velopharynx, wider mCSA at glossopharynx were more likely to achieve a positive outcome with H-UPPP.