This study was carried on 105 apparently and clinically diseased African catfish (C. gariepinus) collected from different localities to study the pathogenicity of Aphanomycosis. Clinical signs of Aphanomycosis in C.gariepinus appeared as dark areas and shallow ulcers with excessive mucous secretion, eroded fins, hemorrhage in borders of dorsal fin, caudal fin, mouth and in jugular groove. In some cases, there is a hemorrhagic protruded anal opening and also some cases exhibit white parts in mouth and fins.