We studied the retention of 15 elements by 11 soils from 10 soil orders to determine the effects of element and soil properties on the magnitude of the Freundlich parametersKdandn. The magnitude ofKdandnwas related to both soil and element properties. Strongly retained elements, such as Cu, Hg, Pb, V, and P had the highestKdvalues. The transition metal cations Co and Ni had similarKdandnvalues, as did the group IIB elements Zn and Cd. Oxyanion species tended to have lowernvalues than did cation species. Soil pH and CEC were significantly correlated with logKdvalues for cation species. High pH and high CEC soils retained greater quantities of the cation species than did low pH and low CEC soils. A significant negative correlation between soil pH and the Freundlich parameternwas observed for cation species, whereas a significant positive correlation between soil pH andnfor Cr(VI) was found. Greater quantities of anion species were retained by soils with high amounts of amorphous iron oxides, aluminum oxides, and amorphous material than were retained by soils with low amounts of these minerals. Several anion species were not retained by high pH soils. Despite the facts that element retention by soils is the result of many interacting processes and that many factors influence retention, significant relationships among retention parameters and soil and element properties exist even among soils with greatly different characteristics.