Cadmium and copper are very toxic heavy metals found in the environment and have public health hazard. Therefore, the current study was performed on 100 samples of fresh water fish (Clarias lazera & Oreochromis niloticus) and marine fish (Sardina pilchardus & Pagrus pagrus) collected at different times from various fish markets in kafr El –sheikh governorate, Egypt. The collected samples were analyzed for determination of their heavy metal residues (cadmium and copper) by Atomic Absorption spectrophotometer (AAS). The obtained results showed that the mean values of cadmium concentrations (mg/kg) were 0.25 ± 0.01, 0.17± 0.01, 0.09 ± 0.01 and 0.08 ± 0.01 in C. lazera, O. niloticus, S. pilchardus and P. pagrus, respectively. While, the average concentrations of copper were 3.05 ± 0.27, 2.62 ± 0.19, 2.10 ± 0.13 and 1.73 ± 0.08 (mg/kg) in such examined samples. The sources of contamination of fresh water and marine fishes with heavy metals and their public health significance as well as some recommendations to control such serious pollutants were discussed.