OBJECTIVE It remains unclear whether elderly patients with compressive cervical myelopathy can be expected to experience a promising surgery-related outcome after undergoing expansive laminoplasty. The purposes of this study were to evaluate the efficacy of expansive laminoplasty in elderly patients with cervical myelopathy due to multisegmental spondylotic canal stenosis and to analyze the effect of preoperative prognostic factors on outcome in elderly compared with younger patients. METHODS The authors reviewed the cases of 22 elderly (> 70 years of age) and 39 younger patients in whom expansive open-door laminoplasty was performed for cervical myelopathy due to multisegmental spondylotic canal stenosis. The pre- and 12-month postoperative clinical symptoms were evaluated using the Japanese Orthopaedic Association (JOA) disability scale. Factors affecting the clinical outcome were statistically analyzed by evaluating the recovery rate calculated from the JOA scale. There were no significant differences in the mean value of the preoperative factors, especially preoperative duration of symptoms and severity of preoperative disease, between the elderly and younger patient groups. In all patients, age at the time of the operation was shown to exert no significant influence on clinical outcome. The mean recovery rate was 58.8% in the elderly group and 61.8% in the younger group, and there was no significant intergroup difference. Improvement or attenuation in impaired upper- and lower-leg motor function was shown in all patients as was an absence in decline of sensory impairment of the extremities. In the elderly group, both the duration of symptoms and the severity of canal stenosis significantly (p < 0.05) affected the clinical outcome. In the younger group, the severity of preoperative symptoms had a significant (p < 0.05) influence on clinical outcome, whereas duration of the symptoms did not appreciably affect clinical improvement. CONCLUSIONS Open-door expansive laminoplasty showed a promising effect on clinical outcome in elderly and younger patients with multisegmental cervical canal stenosis. Significant predictive factors for clinical outcome in the elderly patients were the duration of symptoms and the severity of stenosis, which may involve the static factor causing the cervical myelopathy. To improve the elderly patients' disability, surgery must be performed as early as possible before irreversible changes in the spinal cord develop.