Our aims were to describe clinical characteristics of patients with chronic posterior laryngitis and to predict the response to omeprazole therapy. Ninety-one patients with posterior laryngitis were evaluated by a questionnaire, esophageal manometry and pH recording, and endoscopy. Patients were treated with omeprazole, 20 mg twice daily for 3 months. Therapy was continued another 3 months if necessary. Clinical manifestations of reflux occurred in 84 (92%) patients, abnormal acid reflux in 53 (65%) cases, and esophagitis in 6 of 50 (12%). After 3 months of therapy significant improvement occurred in 30 of 70 patients (41%). Continuing therapy for 3 more months increased the response to 65% (45 of 69 cases). Response to therapy was associated with lower age and lower duration of laryngeal symptoms, but a consistent prediction of the response could not be made. In conclusion, patients with posterior laryngitis frequently present with manifestations of gastroesophageal reflux. Response to therapy can not be predicted with certainty.