Heavy metal contamination has become an important environmental hazard in recent years. In this study a soil-based geochemical survey in the mining district of Ahangaran Malayer (Hamedan province, west of Iran) was carried out. The concentrations of Pb, Zn, Cu, Cd, As, and Sb were determined in 40 topsoil samples. A number of calculation methods have been put forward for quantifying the contamination level of heavy metals on the basis of geoaccumulation index (Igeo), enrichment factor (EF), pollution index (PI). The calculated results of Igeo and EF of heavy metals reveal the order of Igeo is Pb > Sb > Cd > As > Cu > Zn and the order of EF is Pb > Sb > Cd > Zn > Cu > As. The high Igeo and EF for Pb, Sb, and Cd in the soils indicate that there is considerable Pb, Sb, and Cd pollution, which mainly originates from mining activities. The Igeo and EF of Zn, As and Cu are low and the assessment results indicate this pollution is not significant. Assessment results of PI indicate soils are seriously polluted.