A grand total of eighty random samples of Tilapia nilotica and Clarias lazera (40 of each) were
collected after catching in Shebin El-kom, Menofia Governorate. The samples were directly transferred
to the laboratory for determination of their contents of mercury, lead and cadmium. The evaluation
revealed that the mean values of mercury concentration (mg/kg) in the examined fresh water fish were
0.46 ± 0.03 mg/ kg for Tilapia nilotica and 0.52 ± 0.04 mg/ kg for Clarias lazera. Furthermore, the
mean values of lead concentration (mg/kg) in the examined samples of Tilapia nilotica and Clarias
lazera were 0.08 ± 0.02 and 0.14 ± 0.02 mg/ kg, respectively. In addition, the mean values of cadmium
concentration in the examined samples of fresh water fish were 0.10 ± 0.01 mg / kg for Tilapia nilotica
and 0.14 ± 0.02 mg/ kg for Clarias lazera. The public health importance of such heavy metal residues
were discussed.