This chapter discusses the surgery for lumbar canal stenosis. Lumbar spinal stenosis is a reduction in the dimensions of the central or lateral regions of the spinal canal. It occurs most frequently due to chronic degenerative changes. The development of symptoms in a patient is due to the pathophysiologic changes that occur concurrently with the anatomical changes of stenosis. Special attention must be paid to the standing posture of the patient, especially the sagittal alignment. Physical findings are uncommon in patients with spinal stenosis. The main focus of this chapter is on the anatomical considerations, pathophysiology, physical examination, investigation, treatment and nonoperative versus operative treatment. Nonoperative, operative, decompression, laminectomy, laminotomy, microdecompression, lumbar laminoplasty, interspinous distraction devices and decompression and fusion are the treatment options for lumbar canal stenosis. 10 well-colored figures are also provided in this chapter.