Sedation, defined as the depressed level of consciousness, induced by drug administration, is widely used for gastrointestinal endoscopyto relieve a patient’s anxiety and discomfort. In addition, successful procedure is anticipated with control of unintended movements. Endoscopic sedation, however, cannot be free from the risk of serious adverse events, e.g., cardiopulmonary compromise. Therefore,principles on personnel, facility and equipment, as well as performance itself, should be followed to prevent unfavorable incidents. Inthis article, sedation guidelines for the Accreditation of Qualified Endoscopy Units, issued by the Korean Society of GastrointestinalEndoscopy, are presented.