The study dealt with the infestation of Livoneca redmanii (Isopoda, Cymothoidae) on Solea solea in Lake Qarun, Egypt. 487 specimens of S. solea were examined to extract 99 crustacean parasites. Fish specimens were collected monthly from Eastern and Western regions of Lake Qarun, during the period from January to December, 2016. The results showed that S. solea was infested by L. redmanii. The highest infestation recorded was in June b, 38.64 % and the lowest one (10.34 %) in October. The infested fish S. solea were mostly females. The highest male infestation was during March (18.37%) and the lowest in April (2.04%).The highest female infestation was during July (22%) and the lowest in August and October (2%). The highest infestation (37.38%) was in mid length group 14cm and the lowest (1.01%) was in large fish at length group 19cm. The highest infestation (43.44 %) was in weight group 30gm and the lowest one (3.07%) was in largest and smallest fishes at weight group 10 & 70gm. The ecto-parasitic Isopods, L. redmanii infest gills, ventral side, dorsal side, mouth, head and tail sites on the integument of S. solea. The bilateral and/or unilateral infestation per fish was in gills region (73.7%). The main clinical signs in infested S. solea were respiratory distress as surface swimming with opened mouth and gill cover. Also, they showed sluggish movement, emaciation, excessive amounts of mucous covering the body surface. Post-mortum examination showed lesions of focal erosion in skin and gills. Based on the parasitic treatment trails with salinity, the most suitable solution to make control on the parasite blooming was increasing the fresh water flow to adjust the parasite activity and to minimize the optimum condition of blooming.