Lake Nasser is a vast reservoir in southern Egypt and northern Sudan and one of the largest man-made lakes in the world. It has vital importance to Egypt because of the safe water supply of the country. Therefore, the water quality of the lake must be continuously monitored to cope with the challenges of water scarcity and a healthy water supply. Thus, fifteen stations were selected to represent the different habitats of the whole lake in March and July 2019. 9 species of macrobenthic fauna were identified, representing three phyla: Annelida, Arthropoda, and Mollusca with percentages of 74.62%, 15.41% and 9.97%, respectively. The total recorded density was 863 org./m2 and the highest densities were recorded in the southern sectors of the lake. Summer (flood season) exhibited the highest population density.The western station of EL Madiq sector showed the highest Shannon Weaver diversity index (H′= 1.55), which could be attributed to the dominance of 4 species of arthropods, and exclusively, the dominance of nymphs of Ischneura. Contrarily, the middle stations of Wadi Abyad and Aswan sectors recorded the least diversity Shannon Weaver index value (H′= 0.21 and 0.27, respectively) which may be attributed to the nature of the sediment which led to the absence of all mollusk species and the presence of one annelid species (Limnodrilus sp.) and one insect species (Chironomuslarvae). The present study revealed that the number of species decreased dramatically to 9 species compared to 15, 43, 39, and 24 recorded in 1987, 1993, 1995, and 2014, respectively. It is recommended to force an effective legal framework to mitigate pollution in Lake Nasser.