Lumbar spinal stenosis is a common cause of radicular and generalized back pain among older adults. Endoscopic minimally invasive surgery, in contrast to open decompression, may provide the opportunity for a less invasive surgical intervention. Visualization and illumination during the operation can be optimized. Since a more extensive bone or ligament resection is frequently necessary here, a larger diameter endoscope with a correspondingly larger endoscopic working channel and larger instruments and burrs are necessary. After the access has been created, the bony structures are exposed. It may be helpful to start decompression at the caudal end of the descending facet. Depending on the pathology, decompression is then commenced with resection of parts of the medial descending facet, the cranial and caudal lamina, and the ligamentum flavum. The extent of decompression generally continues cranially at least until the tip of the ascending facet and caudally to half of the pedicle. The medial portions of the ascending facet and the ligamentum flavum are then resected until sufficient decompression of the neural structures can be clearly seen. In the case of a central stenosis, the ligamentum flavum generally needs to be resected medially to the midline. If the patient experiences bilateral symptoms of stenosis, an “over the top” access using the undercutting technique to the opposite side is carried out.