The effects of different doses of date palm (Phoenix dactylifera) seed (DPS) extract on heavy metals (Pb, Cd, As, Hg) concentrations of common carp (Cyprinus carpio) were evaluated. The fish (31.6±3.7 g) were assigned to five treatments of three replications each. Five treatments were held using five different DPS extracts at doses of 0% (control), 0.5%, 1%, 2%, and 4%. The results revealed that heavy metals concentrations of fish decreased in the 0.5% and 1% treatments (P<0.05). Hg and Cd concentrations in muscle decreased in all treatments (P<0.05). The results of this research clearly show that the addition of DPS extract to a fish diet has a significant effect on heavy metals concentrations (P<0.05). DPS extracts were shown to be rich in phenolics and flavonoids. Therefore, they have also been discussed as protectants against heavy metal stress. It could be concluded that feeding common carp a diet enriched with DPS extract could decrease heavy metals concentrations that can cause cancer.