Posterior decompression plus posterior reconstruction (laminoplasty) is a useful surgical method for treatment of cervical compresslve myelopathy. There are many laminoplasty procedures. This paper describes the Z-shaped laminoplasty developed by Hattori in 1971, and presents a clinical follow-up of the authors' experience with 130 patients. The procedure involves grinding the laminae down with an air drill and making a Z-shaped cut into the thinned laminae without excising the laminae. This technique enlarges the spinal canal. The purpose of this technique is to decompress the spinal cord and at the same time maintain clinical stability. Postoperative results were satisfactory without any major complication. Follow-up study was conducted in 78 cases with a minimal follow-up period of more than 2 years. Satisfactory clinical results were maintained for long periods postoperatively, and the enlargement of the spinal canal was well maintained as demonstrated on follow up X-ray study.