and Zn were detected in the muscle and gills of Prussian carp from three different freshwater ecosystems: isolated ponds and the South Morava River in Serbia, and Kopačko Lake in complex wetland ecosystem of the Kopački Rit Nature Reserve in Croatia. The main goals of the paper were to assess the concentrations of potentially toxic elements (PTEs) in the muscle and gills of Prussian carp (Carassius gibelio), to examine whether abiotic factors from three different freshwater ecosystems affect the accumulation of PTEs in sh tissues and to estimate the human health risk resulting from sh consumption. There were only six concentrations of PTEs in the gill tissue (Cr, Hg, Mn, Pb, Sn, and Zn) that were not signi cantly different among the different freshwater ecosystems. In the muscles, the differences were much less visible. Kopačko Lake distinguished with the highest values of metal pollution index (MPI) for muscles (0.24) and isolated ponds with the highest values of MPI for gills (0.8). The redundancy analysis (RDA) showed that concentrations of Al, Mn, Zn, Cu, and Fe in the gill tissue were signi cantly correlated with the environmental variables. In contrast, the RDA based on element concentrations in the sh muscles indicated no signi cant relationship with the environment. Isolated ponds, with no in ow of freshwater, stand out as the most polluted, followed by Kopačko Lake with occasional oods. Flowing freshwater ecosystem South Morava River can be single out as at least polluted with PTEs. The target hazard quotients (THQ) and hazard index (HI) suggested there were no signi cant noncarcinogenic health risks. The target carcinogenic risk factor (TR) for As and Pb con rmed there were no cancer risks related to human sh consumption. Since the elevated concentrations of toxic Cd and As in Prussian carp were estimated, an early warning should be assumed, especially for shing activities in these areas.