Extraction of Au-III ions by an emulsion liquid membrane (ELM) system with methyl isobutyl ketone (MIBK) as the mobile carrier and also liquid-liquid extraction of Au-III from aqueous solutions have been studied. Experiments on the transport of the gold ions in a liquid-liquid extraction system and stripping of the extracted ions from the organic phase as well as the extraction by a three-phase W/O/W emulsion liquid membrane system have been performed. The results showed that even when the distribution coefficient of the diffusing species in the phases is small, the extraction by emulsion liquid membranes would be an effective process. A first-order extraction rate was proposed and examined for the extraction system.