We are experiencing the penetration of modern and smart technologies in all sectors of human activity, including mining and geotechnics. One of these technologies is 3D laser scanning, which has seen significant technological advancements over the last decade and has become an integral part of underground construction monitoring as a tool to enable comprehensive, accurate and unbiased capture of the spatial situation in digital form. This development was behind the fact that since 2013, 3D laser scanner has been used by the Institute of Geonics of the Czech Academy of Sciences as a necessary part of the geotechnical monitoring of mine works, when it is possible to precisely detect and quantify the time-space changes caused by man's intervention in the rock mass compared to the traditional established measuring methods. A leading project of recent years was the monitoring of the strain stress state of the rock massif during the 30th seam extraction during the trial operation of the Room and Pillar extraction method in the CSM Mine shaft safety pillar where, besides many other measuring instruments, 3D laser scanning was used for the convergence measuring of roadways, especially for capturing any deformation changes on the permanent pillars. A complementary function was the comparative evaluation with the results of other tools, e.g. with data measured by horizontal extensometers. The subject of the article will be a general description of the possibilities of using 3D laser scanning in geotechnical practice on spatial data acquired during the monitoring lasting almost 3.5 years, when important phenomena were detected in the movement of the pillar walls and the floor heave in the CSM Mine in the tens of cm, sometimes up to 100 cm.