The zoonotic helminths parasitized in tissues of marine water fish clarify the significance of biological pollution in sea water. The incidence and intensity of larval stages of parasites in marine fish were recorded as 44.4%, 43.5% and Zero % in Sebastes marinus, Boops hoops and Sardine pilchardus, respectively, which which were caught from El-Anfoshy Bay. Marine water fish of species Siganus rivulatus, Sardine pilchardus and Boops beeps were caught from El-Mex Bay resulting free from any encystation of metacercariae_ The number of encysted metacercaria per gramme in tissues of the infested marine water fish varied from 1 to 3. These were identified after experimental infection of Ibis ibis as families Heterophyidae and Echinostomatidae. The water samples were taken from El-Anfoshy and El-Mex Bays due to their similarity in hydrobiological features as they are sites of accumulation of some domestic sewage of Alexandria (Thanaa, 1979).