Abstract: Effect of chicken manure extract (CHCME), cow manure extract (COWME) and sewage effluent (SE) on mobilization of Pb, Zn, Cu and Cd, a sandy soil from central region of Saudi Arabia, were studied in columns experiment. All solutions were able to mobilize, only, very small portions (less than 0.55%) of total amount of Pb previously added to soil. The affinity of Pb to soil is higher than the ability of organic and inorganic ligands of CHCME, COWME and SE to form soluble complexes with soil Pb. Although the amounts of soil Zn mobilized in SE (0.16%), COWME (0.55%) and CHCME (3.2%), were relatively higher than those of Pb, Zn ions prefer association with soil solid phase rather than complexing with solution dissolved organic ligands. However, EDTA was able to mobilize higher percentages of soil Pb (49%) and Zn (24%). These results mean that, formation of stable chelates were critical for solublization of solid phase Pb and Zn. Although both SE and COWME had very limited efficiency in mobilizing soil Cu (0.15 and 0.37%, respectively), CHCME had markedly higher one (25%). The dissolved organic ligands of CHCME prove high efficiency, identical to that of EDTA (25%), in forming soluble Cu complexes. Unlike Pb, Zn and to a lesser degree Cu, soil Cd was ready to be mobilized in all leaching solutions, at varied quantities, H2O (7.7%), COWME (10.4%), SE (24%), CHCME (43%) and EDTA (84%). These results verified that soil Cd is distributed among different forms; water soluble, exchangeable and specifically adsorbed on solid phase. Soil Cd tends to be more mobile and available to plant, than Pb, Cu and Zn. Mobilization of soil Cd, Cu, Zn and to a lesser degree Pb, were enhanced by CHCME rather than by COWME and SE.