Sultan Marsh (Turkey) is one of the largest wet lands of the Middle East and Europe. The aim of this study was to determine average concentrations of heavy metals, variations of the obtained values in a large scale, geogenic and anthropogenic sources of the pollution and effects of the pollution on the environment in Sultan Marsh. To these aims, a total of 176 surface soil samples (0-10 cm depth) were collected from 80 ha land in Sultan Marsh. Using a bench-top Spectro-Xepos X-ray fluorescence spectrometer, we analyzed all samples to determine the near-total concentrations of 26 chemical elements. Basic and multivariate statistics were used for statistical analyses. GIS mapping, a powerful tool for identifying possible sources of pollutants, was used to classify and identify the elements. Relatively high concentrations of the elements Fe, Pb, Zn, Sb, W, Mo, Co, Cu, Hg, Ni, Cr, Mn and Cd were found in Sultan Marsh, surrounding rocks (geogenic sources), mines of Fe and Pb/Zn, industrial facilities, residential and agricultural areas and major traffic routes (anthropogenic sources).