<p>Mine-induced landslide hazards constantly occur in the two largest opencast mines in Poland due to their size and great depth. In the paper, examples of landslide investigations and counteraction works performed in these mines are presented. It also discusses the newest research carried out by the author inside the EU RFCS Slopes Project at the Belchatow Mine. The elimination of the risk of mass movement for the mine and spoil dump slopes is impossible. Therefore, early detection of ground displacement is very important. To gain a better understanding of landslide occurrence and triggers, the application of complementary research methods is of particular importance. Modern methods of monitoring, laboratory testing, and modelling can contribute to lowering the risk. The research attempted to evaluate how these techniques could be applied to reliably detect landslide movement. A particular focus was placed on the use of in situ monitoring, satellite high-resolution PSI (persistent scattered interferometry), TLS (terrestrial laser scanning), and LiDAR (light detection and ranging) laser scanning together with numerical modelling and laboratory testing. The project results indicated that each investigation method had benefits and disadvantages. In addition, it is shown that it is very important to carefully calibrate engineering geology data through laboratory tests and available monitoring methods in order to improve slope design safety.</p>