Laboratory batch sorption experiments were conducted to understand the effect of citrate on cadmium sorption to heterogeneous subsurface soils. Our results indicate that citrate may have a pronounced effect on Cd(II) sorption depending on system conditions (e.g. pH, ligand concentration). While the presence of citrate had no effect on Cd(II) sorption at pH <4. it led to a decrease in Cd sorption under slightly acidic to alkaline pH range depending on the concentration of citrate used. Maximum effect of citrate on Cd(II) sorption was observed at pHs between 5 and 7. This coincides with the observed range of maximum citrate adsorption and the formation of Cd-citrate complexes.