Common, gastroesophageal reflux disease (GERD) is promoted by increased abdomino-thoracic pressure gradient and affects a large proportion of patients with obesity. Weight loss is one of the mainstays of conservative treatment. While fundoplication is recognized as the best surgical option in the general population, its results in severely obese individuals are controversial. Roux-en-Y gastric bypass (RYGB) is a widely used bariatric procedure and has been shown to also result in major improvement of GERD through various mechanisms, including weight loss. RYGB is considered by many as the procedure of choice to treat patients with both severe obesity and GERD. Not all patients are free from GERD symptoms after RYGB, though, a therapeutic challenge. This narrative review discusses the complex interactions between obesity, GERD, and RYGB.