Somatostatin has various significant effects on the gastrointestinal tract: it inhibits the release of several gastrointestinal hormones, blocks the exocrine function of the stomach and the pancreas, and decreases the motility of both the stomach and the gut. Its physiological effects make it potentially useful in the therapy of various gastrointestinal diseases and disorders. Somatostatin is effective in the management of active variceal bleeding and increases the effectiveness of sclerotherapy. Previous studies show controversial data about the efficacy of somatostatin in preventing complications following endoscopic retrograde cholangiopancreatography. The use of this compound may be indicated only in high-risk patients in whom endoscopic sphincterotomy may also become necessary. The perioperative use of somatostatin decreases the risk of pancreatic surgery and its application is effective in promoting the closure of pancreatic fistulae. The somatostatin analogue octreotide has a definitive role in the medical management of hormone-secreting neuroendocrine tumours of the gut.