Bariatric surgery is considered to be the most effective treatment modality in maintaining long-term weight reduction and improving obesity-related conditions in morbidly obese patients. In Korea, surgery for morbid obesity was laparoscopic sleeve gastrectomy first performed in 2003. Since 2003, the annual number of bariatric surgeries has markedly increased, including adjustable gastric banding (AGB), Roux-en-Y gastric bypass, sleeve gastrectomy, mini-gastric bypass, and others. In Korea, AGB is much more common than in others countries. A large proportion of doctors, the public, and government misunderstand the necessity and effectiveness of bariatric surgery, believing that bariatric surgery has an unacceptably high morbidity, and that it is not superior to non-surgical treatments to improve obesity and obesity-related diseases. The effectiveness, safety, and cost-effectiveness of bariatric surgery have been well demonstrated. The Korean Society of Metabolic and Bariatric Surgery recommend bariatric surgery confining to morbidly obese patients (body mass index ≥40 or >35 in the presence of significant comorbidities).