We have studied 29 patients for at least five years after canal-expansive laminoplasty for cervical spondylotic myelopathy. The short- and long-term clinical results were compared, and successive radiographs assessed. The long-term clinical outcome was excellent in five patients, good in 12, fair in 11 and poor in one. The mean short- and long-term improvements were 54.4% and 48.5% but patients with focal kyphotic, kyphotic and S-shaped cervical spines did less well, as did those who had a decrease in the index of curvature of the cervical spine of more than 10 at follow-up. Canal-expansive laminoplasty with reconstitution of the posterior soft tissues may help to prevent postoperative malalignment and late neurological deterioration.