3D laser scanning is a unique technology used for the description and subsequent modeling of real\nshape of spatially complex underground mining environment. Groundbreaking was its application in\nthe pilot deployment of the Room and Pillar method at the CSM mine, where this method was used\nfor the first time within the Upper Silesian Coal Basin, also known to have one of the most difficult\nmining and geomechanical conditions in the world. Very difficult mining conditions at depth over 800\nm warranted searching for complex geotechnical tool or method that would capture all changes\nwithout distortion. Despite some shortcomings, 3D laser scanning was selected, although there is still\nno suitable device for dusty and humid mining environment. During the pillar development phase,\ncomprehensive geotechnical monitoring was undertaken including the frequent scanning of pillar\nmovement using 3D laser scanning technology. Based on repeated time-separated measurements,\nspatio-temporal analyses of deformation changes during ongoing mining were carried out. These\nanalyses captured dynamic changes in coal rib, roof and floor movements of designated roadways\nwhile developing the pillar panel. In addition, time dependent long term post-mining measurements\nquantified additional strata movements within the panel enabling assessment of the long term pillar\nand mine roadway stability. The time-lapse scanning indicated variable pillar rib movement with\nmaximum measured displacements of 60 cm. The scans indicated that in most cases, the bottom of the\nseam displaced more than the top of the rib side due to low floor strength causing large floor heave of\nup to 100 cm. During the 3-year monitoring, more than 2 billion spatial points were captured that can\nbe used for further analysis.