The mining industry is facing a variety of geological, technological and social challenges. Future deposits show a general tendency towards increasing depth with complex ores and decreasing grades. One promising approach to deal with low-grade ores is bioleaching in the form of heap and dump operations. Bioleaching is already a state-of-the-art technique, especially for the extraction of copper from sulfide ores. The next step in the development of this technology will be its application as an in situ technology. First attempts to adapt this technology in underground mining in the form of stoping and block caving have already been made. Both methods have to be carried out adjacent to conventional mining operations and therefore require much effort regarding drift development as well as extraction and transport. The adaption of bioleaching as a borehole mining method is the next step to establish an innovative in situ technique to meet future challenges.The Freiberg University of Mining and Technology established the Biohydrometallurgical Centre for Strategic Elements (BHMZ) to foster interdisciplinary research along the whole biohydrometallurgical process chain. In general, 13 different university institutes and several associated groups with about 30 PhD students are mainly focusing on the extraction of indium and germanium from deposits, tailings and recycling material. One of the core projects within the BHMZ is the design and implementation of an underground in situ bioleaching testing facility.This paper demonstrates the potential of in situ bioleaching under technological aspects. Furthermore, different conditioning methods to increase the permeability of the orebody will be explained, and the BHMZ's underground testing facility will be presented.CITATION:Schlueter, R and Mischo, H, 2015. Potential and applications of underground in situ bioleaching, in Proceedings Third International Future Mining Conference, pp 205-212 (The Australasian Institute of Mining and Metallurgy: Melbourne).