The laminoplasty reported in Spine 1982 by the author (H.T.) was modified by a technical improvement to obtain a more reliable enlargement of the cervical spinal canal. The technical improvements and results are described in detail. The osteotomized laminae that floated en bloc like a hinged door must be stabilized by bone blocks with wire ligatures. Thirty patients with severe cervical myelopathy due to multisegmental spondylosis or ossification of posterior longitudinal ligament underwent surgery. The extent of the enlargement of the canal was 4.1 mm on the average in the anteroposterior diameter, and in no case was a significant reduction in the diameter of the canal noted during the follow-up period. A stable and thorough decompression of the spinal canal was noted on the postoperative computed tomograms with satisfactory surgical results.