Abstract: The fish meat is valuable foodstuff of animal source. Environment pollution also water pollution is dangerous for the health and life of organisms which live in it. Water among others can be polluted with heavy metals so, fish from that water can be used as the monitoring organisms for degree of environment pollution with heavy metals. The concentrations of heavy metals higher from allowed can make the fish as animal source, dangerous and harmful for human health. Concentrations of heavy metals (Pb, Cr, Mn, Zn, Cu and Fe) were measured in different organs (liver, kidney, intestine, spleen and skin + muscle) of grass carp (Ctenopharyngodon idella) and bighead carp (Hypophthalmichthys molitrix) and in mud and water from fish farm situated in the continental part of Republic of Croatia. All measurements were carried out by the fluorescence roentgen spectroscopy that uses energy dispersion (Energy Dispersive X-ray Fluorescence method (EDXRF). Significant difference was found between mud, water and fish organ composition (p<0.05) and those between fish tissue for lead (p<0.01) and manganese (p<0.05).