This paper describes the etiology and clinical manifestations of lumbar spinal stenosis (LSS); discusses diagnosis, prognosis, and intervention; and addresses outcome studies and their implications in managing patients with lumbar spinal stenosis. LSS is a condition involving narrowing of the central spinal canal, lateral recesses, or intervertebral foramina; it is the most commonly diagnosed degenerative process associated with aging. Neurogenic intermittent claudication is a common clinical manifestation of LSS that must be differentiated from vascular claudication of the lower extremities. Although surgery is commonly performed in treating LSS, some evidence exists to support the use of a conservative approach such as orthopaedic manual physical therapy. However, controlled clinical trials with large sample sizes are lacking to offer strong support for either conservative or surgical measures. This paper provides a rationale for a manual physical therapy and exercise approach in treating LSS. Future studies need to include comparative research involving different conservative approaches, and indications for surgical versus nonsurgical management of LSS need to be more clearly defined and studied through randomized, controlled clinical trials.