The region of mining activity is shifting in densely populated areas with residential buildings and industries in the Upper Silesian Coal Basin. For this reason, a considerable amount of coal is left as protection pillars under the built-up areas. The longwall mining is not applicable in these areas because significant deformation of the surface is not allowed. To minimise ground movement during underground mining of the shaft protective pillar at the CSM Mine, the modified room and pillar method with stable coal pillar has been experimented. This the first case of application of conventional room and pillar mining in the Upper Silesian Coal Basin. The mining depth ranged between 700 to 900 meters and is perhaps the deepest coal mining experiment by room and pillar method in the world. To determine coal pillar stability during the mining, complex geotechnical monitoring was carried in the panel. Two pillars in diamond shape and with slightly irregular sides were selected as observational stations for the geotechnical monitoring in the first mining panel. To characterize failure of the coal pillars, four 5-level multipoint rib extensometers were used to measure displacements in all sides of the each observational pillar. Frequent measurements of coal pillar deformation were carried out at nine convergence stations using geodetic methods applying a total station. To measure the changes in vertical stress due to mining, four stress cells were installed in each coal pillar. The results of pillar displacement, stress changes and deformation measurements provided valuable inputs to characterize the pillar failure phenomenon, pillar loading, and dynamics of changes, which are described in this paper. It is realised that a combination of these data with a other analyses of the site conditions are essential to establish procedures for a safe room and pillar method of mining in the Upper Silesian Coal Basin.