The AA. describe an endocrine cells presence in the Pig Brunner's duodenal glands by means of histochemical methods at light microscope. Between these they can recognize two types of cells: these enterochromaffins (EC) and these non-enterochromaffins (non-EC), both presents either in the secretory part of the glands or in the deeper parts of the ducts. The EC-cells show generally a prismatic size and their apical part attains the glandular cavity. Their granules are much numerous and recognizables either in the basal part or in other parts of the cells. The non-EC-cells show a variable, from the prismatic to the spheroidal, size. Their granules are numerous and recognizables mostly in the basal part of the cells. Between the non-EC-cells they can also differentiate at least three types: a) these Davenport-positives and poorly argyrophils; b) these Davenport-positives and clearly argyrophils and c) these Davenport-negatives and clearly argyrophils. All cells are by lead-haematoxylin stainables, while by the HCL-BT method the EC-cells are ortochromatics and these non-EC are metachromatics.