Objective: To study the profile of patients with obstructive sleep apnea syndrome (OSAS) and laryngopharyngeal reflux (LPR) at the hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring (HEMII-pH) and to compare their reflux findings with LPR patients without OSAS. Design: Prospective controlled study. Methods: Patients with LPR and OSAS were prospectively recruited from Augustus 2019 to June 2020. The profile of hypopharyngeal reflux events (HRE) of patients was studied through a breakdown of the HEMII-pH findings over the 24-hour of testing. Reflux symptom score (RSS), gastrointestinal and HEMII-pH outcomes were compared between LPR patients and patients with LPR and OSAS. Multivariate analysis was used to study the relationship between reflux data and the following sleep outcomes: Apnea-Hypopnea Index, Epworth Slippiness Scale (ESS) and paradoxical sleep data. Results: A total of 89 patients completed the study. There were 45 patients with LPR and 44 subjects with both OSAS and LPR. The numbers of upright and daytime HREs and the otolaryngological RSS were significantly higher in patients with LPR compared with those with OSAS and LPR. There was a significant positive association between RSS quality of life score and ESS (p=0.001). The occurrence of HREs in the evening was associated with higher ESS (p=0.015). Patients with OSAS, LPR and GERD had higher number of nocturnal HREs compared with those without GERD (p=0.001). Conclusion: The presence of OSAS in LPR patients is associated with less severe HEMII-pH and ear, nose and throat symptoms. There may have different OSAS patient profiles according to the occurrence of GERD.