Objective. General practitioners (GPs) are the first-line physicians who are consulted for upper digestive symptoms. Persons with symptoms may, however, prefer to buy acid inhibitors or antacids in drugstores or pharmacies and bypass a GP. The aim of this work was to study users, reasons for use, and utilization patterns of over-the-counter (OTC) acid inhibitors and antacids in The Netherlands. We also studied factors that were associated with the substitution of OTC acid inhibitors or antacid use for consultation with a GP. Material and methods. From July 2005 to January 2006, persons buying OTC acid inhibitors or antacids in 12 pharmacies and 4 drugstores were asked to complete a questionnaire. A total of 82/160 (51%) questionnaires were returned. Results. Heartburn was the main symptom for buying an acid inhibitor or antacid. Seventy-one (87%) participants substituted OTC drug use for a GP consultation. The most commonly reported reason was the belief that symptoms were not serious enough to seek medical care. Exploratory analyses showed that substitution was less common in participants with comorbidity, a history of upper gastrointestinal disorder, use of an acid inhibitor or antacid previously prescribed by a physician, alarm symptoms (such as pain and nausea), and with being symptomatic for 4 days/week. Conclusions. Although the reasons for substitution of OTC acid inhibitor or antacid use for a GP consultation in The Netherlands do not suggest an a priori increased risk of an underlying serious disorder, it may be advisable for staff in drugstores and pharmacies to provide users with information on appropriate use and when to consult a GP.