The aim of the study was to evaluate the merit of empiric omeprazole therapy in patients with suspected laryngopharyngeal reflux (LPR), to determine the optimal dose and duration of diagnostic test, to compare the diagnostic value of upper gastrointestinal (GI) endoscopy and omeprazole test (OT). One hundred out-patients with posterior laryngitis and more than one atypical symptom of LPR, aged 14-68 years were treated with omeprazole for 4 weeks (clinical group). According to received omeprazole dose (20 mg, 40 mg, > 40 mg), three clinical subgroups were selected. Twenty patients treated only with life style modifications and diet composed dietary group. At the entry to the study, a symptom questionnaire (5 laryngeal and 3 esophageal scored from 0 to 3 points), well being in general (W-B(VAS) on 100-mm VAS scale), videolaryngoscopy, upper endoscopy, and voice assessment (4 voice range profile parameters and overall vocal dysfunction degree (VDD)) were completed. Total symptom index (TSI) was calculated multiplying sum of symptoms severity score by number of presented symptoms. Normal values of efficacy parameters were obtained from 113 healthy voice subjects (control group). Patients were evaluated twice during the treatment: after 1-2 weeks and after 4-5 weeks. Patients were confirmed as responders, if TSI improved at least 50%, and patients were satisfied with results. According to our data, the 1st control assessment showed significant improvement on symptoms, laryngoscopy scores, VDD, and W-B(VAS) only for clinical group patients (p<0.05). Responders rate also was advantageous for the clinical group patients in comparison to the dietary group (36.0% vs. 15%). The second control assessment showed significantly better results for the clinical group patients in comparison to the 1st (p<0.05 2nd vs. the 1st). Sixty five percent of them (65/100) were classified as responders (p<0.05). The better results were in patients receiving omeprazole more than 20 mg daily. Erosive esophagitis during upper GI endoscopy was found for 21.0% (21/100) clinical group patients, 18 of them were responders to omeprazole 4-week test (accuracy of OT with regard to confirmed diagnosis with upper endoscopy was 85.7%). At week 4, efficacy parameters were not in normal range. We concluded that short-term treatment with omeprazole might be useful in confirming the clinically based diagnosis of laryngopharyngeal reflux.