|Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Soonchunhyang University College of Medicine1, Seoul, Eulji University School of Medicine2, Seoul, Kyungpook National University School of Medicine3, Daegu, The Catholic University of Korea College of Medicine4, Seoul, Department of Gastroenterology, Ajou University School of Medicine5, Suwon, Department of Internal Medicine, Yonsei University College of Medicine6, Seoul, Department of Preventive Medicine and Public Health, Ajou University School of Medicine7, Suwon, Steering Committee for Clinical Practice Guideline, Korean Academy of Medical Science8, Department of Preventive Medicine, Ewha Womans University School of Medicine9, Seoul, Department of Surgery, Ajou University School of Medicine10, Suwon, Korea In 2010, a Korean guideline for the management of gastroesophageal reflux disease (GERD) was made by the Korean Society of Neurogastroenterology and Motility, in which the definition and diagnosis of GERD were not included. The aim of this guideline was to update the clinical approach to the diagnosis and management of GERD in adult patients. This guideline was developed by the adaptation process of the ADAPTE framework. Twelve guidelines were retrieved from initial queries through the Appraisal of Guidelines for Research & Evaluation II process. Twenty-seven statements were made as a draft and revised by modified Delphi method. Finally, 24 consensus statements for the definition (n=4), diagnosis (n=7) and management (n=13) of GERD were developed. Multidisciplinary experts participated in the development of the guideline, and the external review of the guideline was conducted at the finalization phase.