We evaluate the patients with lumbar spinal stenosis in multiple levels that were treated with posterior decompression and posterolateral fusion, using transpedicular screw fixation system. Twenty-six patients, mean age 65.7 years (range 49 to 77years), with lumbar spinal stenosis, in more than three levels, were treated surgically between 1994 and 2002. Indications for surgical treatment included low back pain and neurogenic claudication for more than 6 months. The diagnostic approach consisted of x-rays, MRI, myelography and myelo-CT. Oswestry disability score and VAS (visual analog scale), were used for the clinical evaluation of the patients. Surgical procedure consisted of wide posterior decompression, regarding laminectomy, complete or incomplete facetectomy and foraminotomy, combined with posterolateral fusion, using transpedicular screw systems and bone graft. Fusion in three levels was performed at seven patients, in four levels at ten, in five levels at seven, in six and seven levels at one patient respectively. Mean follow-up was 26.8 months (range 12 to 38 months). Oswestry score and VAS revealed improvement 40.75% and 5.4 levels respectively. The better results were concerned to pain (2.88 levels improvement) and the less good to lifting (1.58 levels improvement). Two cases with superficial infections were observed and treated with surgical debridement. Screw breakage was observed in 1 patient and treated conservatively. Loosening of two sacral screws, which were removed, was observed in one patient. We conclude that myelography and myelo-CT revealed with satisfactory accuracy intra and outer foraminal lumbar spinal stenosis. Posterior decompression and instrumented fusion, offer satisfactory clinical results in patients with lumbar spinal stenosis in multiple levels when performed by experienced surgical team.