In the Northern part of Serbia, which is part of Pannonian Basin, mute swan (Cygnus olor) population has notably increased over the last few decades. Like other birds from Anatidae family, mute swans are a host of numerous endoparasite species. The aim of this study was to acquire the data on identification and prevalence of endoparasites in mute swans in the Republic of Serbia, as that information is lacking. Individual faecal samples of sixty-eight adult mute swans were examined for the presence of endoparasites. Coprological examination was performed using flotation and sedimentation technique with saturated ZnSO4 solution. The samples were collected from December 2016 to March 2017, during epizootic of highly pathogenic avian influenza H5N8 in the Republic of Serbia. Dead mute swans were collected from twelve different locations in the Northern part of Serbia. Altogether, 39.7% of the examined fecal samples contained different parasites. The endoparasitic fauna was divers and included 3 species of nematodes, 2 cestodes species, one trematode and one protozoan species. Nematodes were the most prevalent helminthes and among these the most frequent nematode species found was Heterakis dispar (17.6%), followed by Echinuria uncinata (5,8%) and Ascaridia spp. (4,4%). Four mixed infections were found, where double infection was the most prevalent. No endoparasites were found in faecal samples of mute swans collected from the locations Sombor and Titel. As this study covers a small population of mute swans, more detailed studies need to be carried out on a larger population in order to gain an insight into the diversity and prevalence of endoparasites in the Republic of Serbia.