Bioleaching of Ni laterite ores involves the utilisation of fungi organisms and their metabolic products in solubilisation of the metals fractions from ores. High salinity of water supplies and soils in the vicinity of nickel laterite ore bodies is a major abiotic stress to fungi and represents a major challenge in the application of bioleaching process in-situ. To address this issue, Aspergillus foetidus was acclimatised gradually to saline environment to develop its salinity tolerance. The effects of this training on the growth and metabolism of the fungi and leaching behaviour were examined in this study.