In this study, the potential of Eucalyptus oils as green collectors in gold flotation was examined. Flotation tests were conducted on a sample of Boddington's copper-gold sulfide ores. Eucalyptus oil compositions were determined by gas chromatography-mass spectrometry. Gold association of flotation products was investigated by Mineral Liberation Analyzer. It was found that Eucalyptus oils have the potential to replace potassium amyl xanthate as a collector in free gold flotation. The collecting power of Eucalyptus oils is correlated to the percentage of non-polar and weakly polar constituents, and in particular 1,8-cineole, phellendrene and pipertone. Eucalyptus oils possess strong selectivity for free gold rather than gold carriers, and therefore achieve high gold grades at the head of the flotation circuit. (c) 2012 Elsevier Ltd. All rights reserved.