A retrospective study comparing cervical laminoplasty with or without muscle release for the treatment of cervical myelopathy resulting from athetoid cerebral palsy. To assess the effectiveness of muscle release in the treatment of athetoid cerebral palsy. While anterior and/or posterior spinal fusion has been generally accepted as necessary in surgical treatment for cervical myelopathy due to athetoid cerebral palsy, several studies have shown relatively favorable results following laminoplasty. Better results can be obtained by combining muscle release. METHODS.: Study participants were 10 patients who underwent cervical laminoplasty combined with muscle release (mean age, 44.6 years) and 15 patients who underwent cervical laminoplasty alone (mean age, 48.2 years). Therapeutic outcomes 1 year after surgery, as assessed by Kurokawa's methods and JOA scores, were compared between groups. Recovery rate 1 year after surgery was significantly higher for the muscle release group than for the control group. In both groups, recovery rates were significantly better for patients who could walk before surgery. Cervical laminoplasty combined with muscle release for the treatment of cervical myelopathy due to athetoid cerebral palsy is effective in simplifying postoperative therapy and improving JOA scores.