ABSTRACT
         This study was performed on the River Nile at Luxor and Aswan provinces in order to examine, identify and detect both the protozoan diversity and abundance beside some of the physico-chemical variables during periods extending between 2014 and 2016. It was proved that the three main protozoan phyla ( Sarcodina, Mastigophorea with particular reference to Phyto-mastigophorea and Ciliophora) were present in all the examined stations but at different varieties. A total of  66 protozoan genera (11 flagellates, six sarcodines  and  49 ciliates were detected at Aswan sampling stations, while those of Luxor  achieved 41 genera (five flagellates, five sarcodines and 31 ciliates). The highest and lowest numerical densities of the protozoa were obtained on autumn and winter respectively at most of the sampling sites. It was illustrated that dissolved oxygen, phosphate, nitrates, and p^H values  were higher at Aswan  stations as compared with those of Luxor, while  organic matter and water temperatures behaved mostly in an incompatible pattern. From the statistical point of view, organic matter, phosphate and nitrate salts affect significantly the availability of  the protozoa at Luxor stations, while water temperature, P^H, organic matter, phosphate and nitrate salts play a significant role in the prevalence of  these organisms at Aswan. It was proved that protozoa  used as bioindicators for organic pollution such as Carchesium, Opercularia, Vaginicola, Metopus and Epistylis spp. are more abundant at Luxor stations relative to those of Aswan which could be attributed mainly to the Nile crews, other navigation activities  and illegal dumping of sewage.