Azolla filiculoides removed 86% and 100% of gold(III) from initial metal solutions of 2-10 mg gold l(-1) increasing with increased initial concentrations of gold(III). The biomass gave greater than 95% removal efficiency from solution at all biomass concentrations measured. Complete removal of gold occurred at pH 2, with 42% removal at pH 3 and 4, and 63% and 73% removal at pH 5 and 6, respectively. No temperature-dependence removal was observed.