To investigate the minimum therapeutic duration for patients with primary laryngopharyngeal reflux disease (LPRD) through the evaluation of symptom changes at multiple time points. Prospective uncontrolled. University medical center. Patients with LPRD at the 24-hour hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring were recruited from the European Reflux Clinic. Depending on the type of LPRD, patients were treated with a combination of proton-pump inhibitors, alginate, or magaldrate. Symptoms were evaluated with the reflux symptom score (RSS) at baseline and throughout treatment (1-, 3-, 6-, and 9-month posttreatment). The most appropriate therapeutic duration was determined using the RSS changes. Signs were evaluated with the reflux sign assessment. A total of 159 patients completed the study. The mean age was 49.9 ± 15.7 years. At 1-month posttreatment, 97 patients (61.0%) were considered as early responders to treatment, and the treatment was stopped for 52 patients (32.7%). Of the 62 early nonresponders, 34 patients (21.4%) reached responded to treatment after 3 to 9 months. The cumulative therapeutic success rate at 1-month posttreatment (61.0%) progressively increased to reach a range of 82.4% to 99.3% at 9-month posttreatment. The RSS mainly decreased in the first month of treatment in early responders. In early nonresponders, RSS progressively decreased throughout the 9-month treatment period. The baseline severity of RSS is a strong predictor of therapeutic response. A therapeutic regimen of 1 month can be sufficient to treat one third of LPRD patients. The early nonresponders may require 3 to 9 months of treatment.