SummaryEndocrine cells were detected in the gastro‐enteric tract of the fallow deer by means of immunohistochemical procedures, using antibodies against serotonin, somatostatin, gastrin, glucagon and cholecystokinin. The number of cells positive for each antiserum in each region was evaluated. Serotonin‐containing enterochromaffin (Ec) cells were present in every region investigated and were most numerous in the proximal duodenum. Cells positive for somatostatin were present in all the regions studied, with the exception of the colon, and were especially numerous in the proper gastric‐gland region. Cells that were stained by the anti‐gastrin antibody were very numerous in the pyloric‐gland region but only rare in the duodenum. Glucagon‐immunoreactive cells were only detected in the large intestine and their frequency was always less than 10/0.5 mm2. Cholecystokinin‐containing cells were scarce and restricted to the pyloric‐gland region and duodenum.