A total of 258 consecutive decompressive lumbar laminectomies performed on 244 individuals presenting with spinal stenosis were analyzed retrospectively. Spinal fusion was avoided in all but two patients. Outcome in terms of pain relief and return to normal activity was evaluated in two stages, one derived from patient charts and having a relatively short-term follow-up time (mean 8.4 months) and a second derived from patient responses to a questionnaire (which also scored for satisfaction with the results of surgery), which had a longer follow-up time (mean 4.7 years). More than 20 clinical and operative parameters were analyzed. Overall, a high degree of success (93% pain relief, 95% return to normal activity) was achieved in the short term, which was supported by the longer-term follow-up data (64% pain relief, 56% activity return, 75% satisfaction). The following factors were not significantly correlated with outcome: patient age; sex; worker's compensation or no-fault insurance status; employed versus not employed; a history of back surgery prior to the laminectomy studied; existence of degenerative spondylolisthesis or scoliosis; complete versus incomplete myelographic block; or the level of the lumbar spine undergoing surgery. The major conclusions arising from these data are: 1) for all age groups through at least the eighth decade of life, decompressive lumbar laminectomy is a relatively safe operation having a high medium-to-long-term success rate; 2) lumbar instability following laminectomy is rare, even in individuals presenting prior to surgery with degenerative instability conditions; and 3) lumbar fusion in addition to the decompressive laminectomy procedure is rarely required for degenerative spinal stenosis.