Lumbar spinal stenosis (LSS) is a progressive degenerative disease, affecting typically elderly patients and resulting in neurogenic claudication, low back pain, and radicular leg pain with or without neurological deficits. After confirming the diagnosis by imaging studies, conservative treatment including pain medication, physiotherapy, and epidural steroid injections may be used initially, if symptoms are mild. Surgical decompression is the treatment of choice; however, the natural course of the disease is usually unfavorable. We report on the findings of recent randomized controlled trials, providing solid evidence that surgery is beneficial for LSS. Open laminectomy is the traditional surgical approach for LSS but may destabilize the spine by disruption of the posterior ligamentous complex. Today, minimally invasive treatment options exist, including unilateral tubular microsurgery with over-the-top decompression as the gold standard of care. Moreover, monoportal and biportal endoscopic techniques have been developed, which allow for adequate decompression with even less approach-related morbidity. Selected patients with facet joint disease or segmental instability may require decompression and fusion. This chapter provides a balanced overview of treatment modalities, providing patient examples on tubular microsurgery and unilateral biportal endoscopic decompression for illustration.