The assessment of the quality of Digital Terrain Models (DTM) is an important task for mapping organisations. In Europe recently several countries produced a DTM based on laser scanning. Beside the production of new DTMs also the updating of the DTM has to be carried out. Other methods of acquisition and tools for processing may then be necessary. The applications pf DTMs are multiple. Each application has its own requirement. The landscape is very different regarding the amount and type of vegetation and buildings. The checking of the quality of DTMs is therefore a complex task and needs some guidance. This publication provides the basic information for the different tasks in quality control of DTMs.