Obesity is a chronic disease with an increasing prevalence in all groups of age, and is associated to increased general mortality and cardiovascular risk. The multidisciplinary non surgical approach must be the treatment of choice for obese subjects. However, the results of such approach among subjects with severe or morbid obesity, are unsatisfactory. In this group of patients, bariatric surgery and specifically gastric bypass achieves good long term results, maintaining a low body mass index, reducing complications and improving quality of life. Considering the widespread practice of bariatric surgery in Chile, the Nutrition Unit of the Ministry of Health formed a task force to propose update guidelines for the surgical treatment of obesity. These guidelines were proposed after a thorough literature review and discussion with groups that practice bariatric surgery using defined protocols. This document provides a summarized version of the guidelines. The first section discusses the background for bariatric surgery and the second part give specific recommendations for patient management and the formation of reference centers for surgical management of obesity.