Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) were analysed in topsoil and in Quercus ilex L. leaves from holm oak woodlands located along urbanization gradients (urban, periurban and extraurban sites) in two Italian regions (Campania and Tuscany). In each sampling site, the metal bioavailability factors (MBFs) and the pollutant bioaccumulation factors (BAFs) were calculated to estimate the fraction of each total metal concentration in soil potentially available to root uptake and to know the fate of both HMs and PAHs in the plant–soil system.