The distributions of Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn in water, sediment, and six fish species (Barbus grypus, Barbus luteus, Barbus sharpeyi, Cyprinus carpio, Liza abu, and Silurius trisostegus) in the most important and largest wetland in southwest, Iran were determined. The concentrations of vanadium (0.10–0.37mgL−1) and lead (0.63–0.12mgL−1) in water and manganese (153.1–420.1mgkg−1), and nickel (17.8–79.21mgkg−1) in sediment were high among other elements. Accumulation of trace elements in muscle of studied fishes was related to Zn (28.57–49.50mgkg−1), Mn (1.03–24.80mgkg−1), V (4.87–6.75mgkg−1), Pb (2.90–6.39mgkg−1), Cu (3.21–5.00mgkg−1), Ni (0.96–2.63mgkg−1), Cr (0.7–2.60mgkg−1), Co (0.41–1.26mgkg−1) and Cd (0.13–0.41mgkg−1). Also, concentration levels of all studied elements in whole body of L. abu were the highest. The potential uptake of toxic elements including Cd, Cr, Co, Ni and Pb in muscle of studied fish species decreases as B. luteus>C. carpio>B. sharpeyi>B. luteus.