Morphological and histological studies are very useful for the characterization of the digestive tract, which provides important information for understanding the feeding habits and digestive physiology of fish. This paper presents the results of research of the histological structure of the digestive system of the endemic fish Salmo obtusirostris (Heckel, 1851) from the Buna River (Neretva River basin, Bosnia and Herzegovina). According to IUCN Red List, S. obtusirostris is considered Endangered B2ab (v) ver. 3.1, with decreasing population trend throughout its distribution area. A specimen (TL = 265 mm, SL = 245 mm, m = 251.52 g) of the species S. obtusirostris was caught in the Buna River in May 2019. As the basic material, digestive tract of the above-mentioned species was used, divided into esophagus, stomach, pyloric appendages, intestine, as well as the digestive glands, the liver and the pancreas. By using basic histological techniques, microscopic preparations were made from the tissues. When studying the microscopic structure of the organs of the digestive system of S. obtusirostris, it was established that the majority basically consists of mucosa (tunica mucosa), submucosa (tunica submucosa), muscular layer (tunica muscularis) and outer layer (tunica serosa). The histological structure of the digestive system of S. obtusirostris Heckel, 1851 is consistent with its diet.