Atrophy of the pancreatic remnant after pancreaticoduodenectomy might be consequent to dereg- ulation of pancreatic endocrine stimuli after duodenal removal. Relative technical surgical solu- tion could be the anastomosis of the 1st jejunal loop to the stomach and the 2nd to the pancreatic stump. Data on the distribution of endocrine cells within the proximal intestine might represent the lacking tile of the problem. Our aims were to investigate the distribution pattern of seroto- nin, cholecystokinin and secretin cells in the duodenum, the 1st and 2nd jejunal loops of humans. Bowel specimens of ten patients submitted to pancreaticoduodenectomy were collected; immuno- histochemical reactions and morphometric analyses were performed. A general ab-oral decrease of enteroendocrine cells was found. The rate of serotonin cells showed a significant 30.67±8.13% reduction starting from the 1s' jejunal loop versus duodenum. The rate of both cholecystokinin and secretin cells in the duodenum was superimposable to that in the 1st jejunal loop, with a sig- nificant 62.88±4.80% loss of cholecystokinin and 39.5±9.31% of secretin cells in the 2nd loop. After removal of duodenum, preservation of the 1st jejunal loop could impact the function of pancreatic remnant maintaining the physiological enteroendocrine stimulus for pancreatic secretion that can compensate, at least in part for the abolished duodenal hormonal release.