Bariatric surgery is considered the most effective treatment modality for treatment of obesity and related comorbid conditions. Bariatric surgery was introduced in the early 1950s. However, the bariatric "revolution" occurred during the late 1990s and early 2000s, which led to an exponential increase of bariatric procedures performed. This phenomenon occurred because of three events: the rapid increase of obesity rate, the introduction of laparoscopic technique, and the role of the mass media, including the internet. In Korea, surgery for obesity started in Jan. 2003 when the first laparoscopic sleeve gastrectomy was performed by Won Woo Kim (from The Catholic University of Korea). During the same year, laparoscopic gastric bypass was performed by several surgeons at 3 different institutions. Seung Ho Choi from Yonsei University, Eung Kook Kim and Sang Kuon Lee from The Catholic University of Korea, and Kyung Yul Hur (mini-gastric bypass) from Hansol Hospital performed gastric bypass laparoscopically. The next year, LAP-BAND(R) device was approved by KFDA and the first laparoscopic adjustable gastric banding was performed by Eung Kook Kim and Sang Kuon Lee from The Catholic University of Korea in Aug. 2004. In 2009, a new procedure, the duodenojejunal bypass, was first introduced in Korea, mainly for metabolic purpose. This procedure was performed by three surgeons in three different institutions, Eung Kook Kim from The Catholic University of Korea, Seung Ho Choi from Yonsei University, and Yoon Seok Heo from Inha University. In 2011, the first robotic-assisted gastric bypass was performed by Do Joong Park from Seoul National University. In 2009, the Korean Society for Metabolic and Bariatric Surgery (KSMBS) was founded and in 2012, it became an official member of the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO).