The initial determination of the rock mass characteristics and its behaviour has been a key parameter to ensure that a safe and economical extraction can be achieved at Granny Smith Gold Mine (GSGM). The objective of this paper is to outline the geotechnical and planning approach that has been followed to ensure that the intended stoping performance is reached. The geotechnical analysis involves the use of geological and structural analysis, empirical design methodologies and numerical analysis/simulation to determine the effects of induced stresses on the overall stability of the open stopes as well as to the adjacent excavations. Stope and pillar design, size and placement are optimised with the aim to maximise extraction without compromise to personnel safety and global mine stability. The reinforcement requirements for accesses and adjacent excavations to the stoping areas are determined at the planning stage with the aid of numerical modelling. https://papers.acg.uwa.edu.au/p/1511_10_Machuca/ Geotechnical approach to stope and pillar optimisation at Granny Smith Mine L Machuca et al.