The present study was carried out on 160 catfish Clarias lazera collected from upper Egypt. The study revealed four different species of protozoa branchialsis; myxobolus spheroidalis; Trichodina fultoni and Trypanosoma mukasai in percentage of 35.5%, 22.6%, 21.0% and 21.0% respectively. While the total percentage of infected fish was (38.75%). The present study candied that the highest percentage of isolated their previous protozoal infection occurred during Summer season and the lowest in winter season. On the other hand, the infection of Trypanosoma mukasai was higher during winter season and lower in Summer season.