Morbid obesity is becoming a serious public health problem worldwide. In Asian countries, the prevalence has increased many times over in the past few decades. Bariatric surgery has been shown to be the most effective treatment for these patients. The primary goal of bariatric surgery is to reduce the body weight or the body mass index (BMI). However, it is increasingly recognized that this surgery can also help several medical comorbidities associated with obesity such as type 2 diabetes mellitus (T2DM), dyslipidemia, obstructive sleep apnea etc. linical guidelines for bariatric surgery were frst suggested by the NIH (National Institutes of Health) in 1991 and over the past few decades, there have been many modifcations introduced by many national and international societies. BMI cutoff points and co-morbidities are commonly used to defne the indications for bariatric surgery. According to the world health organization (WHO) criteria, BMI cutoffs for obesity in Asian population are lower than the Western countries because obesity associated health risks tend to occur at a lower threshold of BMI in Asians . This aim of this chapter was to review the indications for bariatric surgery from many guidelines worldwide, especially in Asian countries. The discussed guidelines include those by the National Institutes of Health, Asian Pacifc Metabolic and Bariatric Surgery Society, Diabetes Surgery Summit, Obesity Surgery Society of Australia and New Zealand, Asian Consensus Meeting of Metabolic Surgery, Asian Diabetes Surgery Summit, The International Diabetes Federation, The International Federation for the Surgery of Obesity-Asia Pacifc, American Society for Metabolic & Bariatric Surgery and the International Federation for the Surgery of ObesityEuropean guidelines.