Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 15 2 2020 06 09 282 286 Seyed Mohammad HOSSEINI Department of Pathology, Babol Branch, Islamic Azad University, Babol, Iran Amir Hossein MOSHREFI Young Researchers and Elite Club, Babol Branch, Islamic Azad University, Babol, Iran Aryan ESFANDIYARI Young Researchers and Elite Club, Babol Branch, Islamic Azad University, Babol, Iran Mohammad Reza YOUSSEFI Department of Veterinary Parasitology, Babol Branch, Islamic Azad University, Babol, Iran Alireza NASSIRI Young Researchers and Elite Club, Babol Branch, Islamic Azad University, Babol, Iran 2020 06 09 According to the last information of IUCN Red List, Eurasian lynx has been endangered since 2010. The population of this animal is heavily affected by infectious parasites. Two adult Eurasian lynx (one male and one female) were illegally hunted and found dead in Parvar National Park, Semnan Province, Iran. After the autopsy, the tissue and parasite samples were collected from gastrointestinal tract and transferred to 70% alcohol. Samples were recovered and identified as Joyeuxiella spp.  Sonsino, 1889. Tissue samples were taken from the place of sticking of parasites on the intestinal wall, for histopathological examination, and were transferred to 10% buffered formalin. Following routine processes and H&E staining, the slides were examined microscopically. Main histopathological observations were epithelial hyperplasia and destruction, inflammatory cell infiltration in mucosa and submucosa of jejunum. To the best of the author’s knowledge, this is the first report and histopathological study of Joyeuxiella spp. in the world in Eurasian lynx. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/2953 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/2953/1043