Chlorinated pesticide production, use and disposal, has contributed significantly to polychlorinated dibenzo-p-dioxins and dibenzofuran (PCDD/F) contamination in the environment. Global pesticide application has been and continues to be extensive, including those which are known to contain or potentially contain PCDD/Fs. The aim of this study was to investigate the significance of pesticides as historical and current sources of PCDD/Fs to the Australian environment by determining their levels in a range of different formulations. PCDD/Fs were detected in all pesticide formulations analysed in this study at concentrations ranging from 0.0081 to 1,000 ng PCDD/F g-1 formulation (0.037 to 2,100 ng PCDD/F g-1 active ingredient), with the highest levels detected in current use pesticides containing pentachloronitrobenzene (PCNB). For most pesticides, data on volume of use are not available in Australia. However, using estimates based on market value and use volume trend data, label information and respective application area in Australia, pesticides have the potential to contribute significantly to the current PCDD/F emissions in Australia