Diffusive gradients in thin films (DGT) has been used for the assessment of Zn availability and offers some advantages over routine batch extractions of soil samples. To evaluate the effectiveness of DGT compared with CaCl2-extraction to P additions in Zn contaminated soil, a greenhouse study was established. Zinc was added at the rate of 0, 150, 300, 600 and 1200mg Zn kg(-1) as ZnSO4 in order to create various levels of Zn phytoavailability. Soil was amended with KH2PO4 at 0, 100 and 200mg P kg(-1). Increasing application of Zn to soil elevated Zn adsorption by DGT, plant Zn concentrations, CaCl2 extractable and water-soluble Zn and decreased soil bioavailable P and pH. Internal plant concentrations and CaCl2-extraction were influenced by P additions, whereas DGT Zn concentrations were not affected. Phosphorus application decreased plant Zn concentrations and increased plant biomass yields.