To investigate the prevalence and features of laryngopharyngeal reflux (LPR) in patients with primary burning mouth syndrome (BMS). Prospective uncontrolled study. Patients who visited our Departments of Otolaryngology-Head and Neck and Maxillofacial surgery with BMS were prospectively recruited from September 2018 to September 2020. Patients benefited from dental, maxillofacial, otolaryngological examinations, and hypopharyngeal-esophageal impedance pH-monitoring (HEMII-pH). Oral, pharyngeal, and laryngeal findings and symptoms were rated with Reflux Sign Assessment (RSA) and Reflux Symptom Score-12 (RSS-12). Patients were treated with a combination of diet, pantoprazole, and alginate. From the 81 included patients, 76 reported >1 pharyngeal reflux events (93.8%), accounting for 35 (46.1%), 24 (31.6%), and 17 (22.3%) acid, mixed, and nonacid LPR, respectively. Thirty-two patients had both LPR and gastroesophageal reflux disease (GERD). Thirty-eight patients benefited from pepsin saliva measurement, which was positive in 86.8% of cases. The mean scores of mouth/tongue burning, RSS-12, and RSA significantly improved from pre- to post-treatment (P < .004). At 3-month post-treatment, 62.5% of patients reported an improvement of mouth/tongue burning score. Patients with both GERD and LPR reported higher baseline RSS-12 and RSA scores. Acid, weakly acid, and nonacid LPR may be involved in the development of BMS. The use of an appropriate treatment considering the reflux features is associated with an improvement of symptoms and findings. 4 Laryngoscope, 131:E2627-E2633, 2021. © 2021 The American Laryngological, Rhinological and Otological Society, Inc..