A total of 600 fresh water fish (Mugil sp., Tilapia sp. and Carp sp.) were collected from Abbassa aquaculture (harkia province), Qaroun and Wadi Al-Raiyan lakes (Fayom province). The prevalence of encysted metacercarial infestation in fishes from Abbassa aquaculture, Qaroun and Wadi Al-Raiyan lakes were 59.5%, 5% and 53% respectively. Eight types of encysted metacercariae were detected in fishes. The isolated metacercariae were experimentally fed to fish eating mammals (cat and rat) and birds (pigeon and heron) producing fourteen types of trematode species, where, all of them are of zoonotic importance except the Diplostomum Tilapi. Concerning the estimation of bioaccumulation of some heavy metals as lead (Pb), Cadmium (Cd), Mercury (Hg), Copper (Cu) and Zinc (Zn) in fish flesh recommended in the study were higher in heavily infested fishes, where, the levels of lead and mercury residues in examined fishes from Abbassa aquaculture and Qaroun lake were higher than those of WHO limits (1984). The detectable residues of other heavy metales were within the permissible limit. A negative correlation between the rate of metacercarial infestation and the native score of accepted sensory evaluation was also demonestrated. Application of physical control for killing the metacercarial parasitic encystation in fish with thermal procedures as frying, grilling and microwaving revealed 5 minutes, 10 minutes at 60-80°C and 5 minutes at high power, respectively, while, freezing for 72 hours at - 4°C and 48 hours at - 18°C were sufficient to kill all encysted metacercariae in the tested fish flesh.