The aim of the present review was to evaluate the effects of neurotensin on the exocrine pancreatic secretion. Neurotensin immunoreactivity has been identified in the central nervous system and also in the digestive system, where it is found in specific endocrine cells of the intestinal mucosa (N cells), in nerve fibers of the enteric nervous system and in intrapancreatic ganglia (both in nerves and cell bodies). Studies in laboratory animals and in humans have demonstrated that the ingestion of a meal causes a significant release of neurotensin into the circulation and that exogenous administration of low doses of the peptide strongly stimulates exocrine pancreatic secretion. These findings, together with the demonstration that the immunoneutralization of circulating neurotensin significantly reduces the pancreatic secretory response to a meal, suggest that neurotensin is a physiological regulator of exocrine pancreatic secretion.