The link between obesity and GERD is clear on all measures of the disease: clinical symptoms, erosive oesophagitis, acid esophageal exposure, and complications. The pathogenesis of this link may be due to general factors such as visceral adiposity, oestrogen levels, or decrease of Helicobacter pylori infection with increased gastric acid secretion. Increased abdominal pressure leads to disruption of the esophago-gastric junction and hiatal hernia, and esophageal motility may be modified by obesity. Weight loss does improve GERD, but lifestyle modifications and diet are usually insufficient in the long-term for morbid obesity. GERD and hiatal hernia are key issues in bariatric surgery, and are widely discussed because of important implications. It is not currently certain which procedure should be favoured in case of GERD; yet gastric bypass offers the best guarantee of success. Hiatal hernia repair is also deemed necessary by some authors at the same time of the bariatric surgery. Minimally invasive techniques pose a new challenge to this issue, both technically and theoretically.