**1. Introduction**

Obesity is now considered an epidemic worldwide and rising at an alarming rate. Not only does obesity increase the chance of developing debilitating comorbidities and affects the quality of life, but also has a major load on health systems and increases costs [1]. One of the most effective tools to tackle obesity is bariatric surgery. It showed remarkable and durable results compared to other means, such as lifestyle changes and intensive medical management [2]. Despite its effectiveness, due to the sedentary lifestyle and the availability of calorie-dense foods, in addition to other factors, weight regain or failure to lose is becoming more prevalent. Other issues of surgical intervention, in general, are the possible occurrence of surgery-related specific complications. Hence, revisional surgery is becoming more popular recently to address these inconveniences. This chapter will address the most common revisional bariatric surgeries practiced.
