In this study, the effects of fish diet contaminated with Cu, Cd and Cu + Cd on Nile tilapia, was demonstrated by evaluating its bioaccumulation in the muscle and by testing the cytogenetic profile. Fish exposed to diet contaminated with Cu, Cd or their mixture had a significant increase in the number of chromosomal abnormalities and an inhibition of the mitotic index. Our study revealed high muscle Cu or Cd content in fish fed with diet contaminated with high dietborne Cu, Cd, Cu and Cd. It also revealed that the chromosomal abnormalities were higher for fish fed diet Cd contaminated and Cu + Cd contaminated diets than those fed diet Cu contaminated diet. Thus, maybe fish diets contaminated with Cu, Cd, Cu + Cd induced genotoxicity and mutation. Also, maybe high concentrations of Cu and Cd in fish tissue resulted from feeding on Cu and Cd contaminated diets, are dangerous for human consumption.