A total of 120 hake fish (Saurus tumbil); 37 Egyptian eel (Anguilla anguilla) and 56 Mugil sp. (Mugil cephalus) were collected from Ismailia and Suez Province to investigate the seasonal prevalence of microsporidiosis and the associated pathological changes. The infestation rates in Saurus tumbil, Anguilla anguilla and Mugil cephalus were 10.8%, 8.1% and 0% respectively. The infected fish revealed no pathognomonic clinical signs except slight abdominal distension in some fish. The fish specimen showed small white to yellowish-white cysts or nodules with different sizes and the intensity of nodules was 1-8 per fish in Saurus tumbil and 1-4/fish in Anguilla anguilla which embedded subcutaneously in the musculature and some internal organs. The highest prevalence of infection was recorded in summer (23.3%, 20% and 0% in Saurus tumbil, Anguilla anguilla and Mugil cephalus respectively). The histopathological examination revealed degeneration, oedema and necrosis in organs and muscles of the infected fishes.