In-Situ Leaching (ISL) involves the extraction of uranium by delivering a solution through well bores into an underground uranium ore-body. The solution dissolves the uranium and is intercepted and pumped to the surface for processing. The ISL process is an economically attractive method for extracting uranium ore from low-strength saturated sands or sandstones. The nature of the process, however, is such that it requires an ore deposit to occur in permeable saturated sands, which introduces elements of environmental risk to groundwater systems.This report reviews the practice of ISL uranium mining and its application to Australian uranium deposits. Environmental concerns are discussed, including:• Groundwater sources and use;• Groundwater contamination;• Excursions of leach solution;• Radiological contamination;• Regulation and oversight; and• Rehabilitation.Details of measures in place in Australia to limit these risks are presented in conjunction with applicable Australian legislation and regulation. Previous experience over the last forty years of ISL mining has been reviewed and evaluated with a view to understanding why many mines have left a legacy of contamination and others have been successfully rehabilitated.Based on available literature and lessons gleaned from early practice of the method, this review concludes that In-Situ Leach mining of uranium would be beneficial to the Australian uranium industry and that the processes currently used are superior to conventional mining methods. Environmental risks are evident, as they are in any project, but the current legislation, regulation and environmental protection processes satisfactorily address and minimize these risks.