Lumbar stenosis includes various forms of constriction of the spinal canal or the intervertebral foramen. Stenosis may be present in isolation, with or without a disc bulge or herniation, or can be associated with degenerative spondylolisthesis or degenerative scoliosis. This article analyzes the indication for surgery and the methods and outcomes of operative treatment in central, lateral, and foraminal stenosis either isolated or associated with other conditions. The factors that most affect outcome are correct indications for surgery and adequate technique. At present, 70-80% of patients have a satisfactory result from surgery, but the outcome tends to deteriorate in the long term.