© 2021 Lippincott Williams and Wilkins. All rights reserved.Proton pump inhibitors are the commonly prescribed drugs for acid-related disorders. However, many of those prescriptions are inappropriate in inpatient and outpatient settings according to the recommended guidelines. Many studies have been conducted in inpatient clinics, but data about the appropriateness of proton pump inhibitor prescribing in outpatient clinics are scarce. Therefore, the aim of this study was to determine inappropriate proton pump inhibitor prescribing rates among patients admitted to a tertiary hospital family medicine outpatient clinic. A total of 259 patients (median age = 59 years; 72.6% women) were enrolled into the study and 35.9% of them had no proper indications to utilize proton pump inhibitors. Inappropriate proton pump inhibitor usage rate was significantly higher in patients older than 60 years compared with their younger counterparts (62.4% vs. 37.6%; p =.001). The most frequent reason to use a proton pump inhibitor with nonapproved indications was polypharmacy (41.9%). Despite endoscopic evaluation, 41.9% of the patients received a proton pump inhibitor without an approved indication. A significant proportion of nonindicated prescriptions were a consequence of continued prescribing without re-evaluating patients in outpatient clinics. Consideration of proton pump inhibitor indications according to the guidelines in every admission may prevent inappropriate prescriptions.