This study is designed to investigate the role of (0,1,2 and 3.0% by weight) Portland cement, hydrated lime, gypsum and bitumen in the stabilization mechanisms of many lead contaminated Iraqi soils; as measured mechanically by a “mini” JET device and chemically by the gravimetric dispersion ratio method (as DR,%) in 1:2 soil:water solutions. From the “mini” JET results, cement was the best mechanical stabilizer in increasing both the critical shear stress (τc, pa) and the degree of hardness (DH) and hence reducing both the scouring depth (SD, mm) and the erodibility coefficient (kd cm3/N.s); followed by lime and bitumen. Gypsum has proved its failure as a mechanical binder and its calcium produced flocks seem to be very vulnerable against wet conditions and the energy of running water scouring force. To the contrary and as a chemical stabilizer, gypsum was superior in reducing the dispersion ratio (DR,%); followed by lime, cement and bitumen. In the case of lead mobility, gypsum was the best in reducing lead solubility and presumably its mobility in treated soil solutions; followed by bitumen, cement and lime with a stabilization efficiency (SE,%) of 93,90,59 and 54.9% respectively, but the formed gypsum calcium-clay flocks loaded with lead may be easily detached by the running water forces