Acanthogyrus tilapiae (Baylis, 1948) was isolated from the intestines of wild (from River Nile) and cultured (from ponds beside River Nile) Nile tilapia Oreochromis niloticus in Assiut city, Egypt.  The study extended over one year starting from December 2013 to November 2014. The overall infection rate was 12.84%, while was 11.80% with a mean intensity of 4.70 in the wild fish, and was 13.19% with a mean intensity of 2.68 in the cultured fish. The highest infection rate was recorded in winter in both wild (36.1%) and cultured (33.3%) fish.  Males have insignificantly higher infection rates than females in both wild and cultured fish. There was a positive correlation between fish length (age) and A. tilapiae infection rates where larger (older) fish showed significantly higher infection rates then younger fish. The parasite was found mainly in the anterior two thirds of the intestine with the lowest number of the parasite detected in the posterior third. Histopathologically, the intestine of fish infected showed parasitic enteritis with lytic necrosis in the intestinal mucosa which associated with eosinophilic cell reaction.