The tilapia Sarotherodon melanotheron is a fish species widely used in African fish farming due to its high market demand. It represented a significant proportion of the fish fauna in Taabo manmade lake in particular. However, the stock of this fish is facing parasitic infestation which deteriorates it considerably. In addition, there is no data on the parasitic epidemiology of this fish in this environment. These data are essential to finding strategies to avoid huge fish losses in the natural and the breeding environment. From March 2023 to April 2024, 1107 specimens of S. melanotheron were captured in this lake in order to study some aspects of their gill monogenean parasites. After host sampling and parasites mounting standard methods of parasitological examination were used for identification of monogenean species. Gill helminthofauna of this fish consisted of Cichlidogyrus acerbus, C. halli, C. halinus, C. lagoonaris and Scutogyrus minus. The fish captured in Ahondo station were the most infested. The infestation exhibited seasonal fluctuation with the maximum parasite species were recorded in the rainy seasons and the minimum one in the dry seasons. It was observed that the sex of this fish have an influence on parasitism infestation. These results could help to improve the productivity of this fish.