The July issue of Clinical Endoscopy deals with selected articles covering the state-of-the-art lectures delivered during the 50th seminar of the Korean Society of Gastrointestinal Endoscopy (KSGE) on March 30, 2014, highlighting educational contents pertaining to either diagnostic or therapeutic gastrointestinal (GI) endoscopy, which contain fundamental and essential points in GI endoscopy. KSGE is very proud of its seminar, which has been presented twice a year for the last 25 years, and hosted more than 3,500 participants at the current meeting. KSGE seminar is positioned as one of premier state-of-the-art seminars for endoscopy, covering topics for novice endoscopists and advanced experts, as well as diagnostic and therapeutic endoscopy. The 50th KSGE seminar consists of more than 20 sessions, including a single special lecture, concurrent sessions for GI endoscopy nurses, and sessions exploring new technologies. Nine articles were selected from these prestigious lectures, and invited for publication in this special issue. This introductory review, prepared by the editors of Clinical Endoscopy, highlights core contents divided into four sessions: upper GI tract, lower GI tract, pancreatobiliary system, and other specialized topic sessions, including live demonstrations and hands-on courses.