Grouting with polyurethane [PU] resins represents an effective method of improvement of mechanical and sealing properties of soil and rock environment and constructions. The principle of grouting technologies is injection of liquid grouting material into the rock environment or construction under pressure. During the grouting process, fissures and pores are filled with the grouting material, which subsequently hardens and connects the disintegrated parts of the rock mass or grains of loose material. Polyurethane grouting technologies started to be used in the 80s of the 20th century in the mining industry. In the last recent years, PU grouting technologies spread significantly from the mining applications to civil engineering and geotechnics. The application possibilities have a rising tendency and new possibilities occur. Currently, grouting technologies are used mainly in the following fields: