Dumping syndrome is a frequent complication of esophageal, gastric or bariatric surgery. Rapid gastric emptying, with the delivery to the small intestine of a significant proportion of solid food as large particles that are difficult to digest, is a key event in the pathogenesis of this syndrome. This occurrence causes a shift of fluid from the intravascular component to the intestinal lumen, which results in cardiovascular symptoms, release of several gastrointestinal and pancreatic hormones and late postprandial hypoglycemia. Early dumping symptoms comprise both gastrointestinal and vasomotor symptoms. Late dumping symptoms are the result of reactive hypoglycemia. Besides the assessment of clinical alertness and endoscopic or radiological imaging, a modified oral glucose tolerance test might help to establish a diagnosis. The first step in treating dumping syndrome is the introduction of dietary measures. Acarbose can be added to these measures for patients with hypoglycemia, whereas several studies advocate guar gum or pectin to slow gastric emptying. Somatostatin analogs are the most effective medical therapy for dumping syndrome, and a slow-release preparation is the treatment of choice. In patients with treatment-refractory dumping syndrome, surgical reintervention or continuous enteral feeding can be considered, but the outcomes of such approaches are variable.