Spinal stenosis presents with the patient complaining that walking a certain distance causes leg pain or leg weakness. The underlying cause is narrowing of the spinal canal, resulting in nerve root compression. The resulting claudication or leg pain is actually vascular in origin. The nerve roots cannot receive the necessary blood supply because of the mechanical compression, and that restriction is the cause of the leg pain and why the characteristic claudication leg pain presents in a fashion similar to the claudication symptoms seen with peripheral vascular disease. If the problem is severe enough, the treatment is decompression of the appropriate nerve roots. Usually decompression can be performed without any instrumentation or fusion. For certain conditions, however, these additional surgical modalities are necessary to provide the patient with a lasting good result. Several medical, social, psychological, and nutritional factors should be evaluated preoperatively. The goal of the surgery is to allow the patient to walk longer distances and, therefore, to be a more functional member of society. With appropriate treatment and preoperative medical evaluation, we find that roughly 85% of patients are significantly helped with surgical treatment, 12% feel that they are not significantly better, and 3% feel they are worse. The incidence of serious postoperative complications has been surprisingly low.