Upper extremity sensory disturbances are primary symptoms that affect the quality of life (QOL) of patients with cervical spondylotic myelopathy. Although laminoplasty is 1 of the surgical options, its effects on sensory disturbances have remained unclear. We aimed to determine whether surgical intervention would improve the sensory disturbances of patients with cervical spondylotic myelopathy. We conducted a prospective clinical trial of 101 patients who had undergone open door laminoplasty. For an objective sensory assessment, we measured the current perception thresholds (CPTs) in the patients' forearms and palms using PainVision PS-2100. For a subjective sensory assessment, numbness in the upper extremities was rated using a visual analog scale (VAS). Using the VAS scores, the patients were divided into those with improvement and without improvement. Their self-reported 36-item short-form health survey and Japanese Orthopaedic Association cervical myelopathy evaluation questionnaire scores were compared. The postoperative CPTs in relationship to the preoperative CPTs at 3, 6, and 12 months was 99.3%, 98.1%, and 93.8% in the forearm and 93.6%, 90.6%, and 87.8% in the palm, respectively. The corresponding postoperative numbness VAS scores were 63.8%, 50.5%, and 48.0%. At 12 months postoperatively, the 36-item short-form health survey physical and role component summary scores, cervical spine function effectiveness rates, upper and lower extremity function, and QOL items in the Japanese Orthopaedic Association cervical myelopathy evaluation questionnaire were significantly higher in the improvement group. Our findings have indicated that improvement in postoperative subjective sensory disturbances will occur relatively earlier and will be significantly greater than the improvement in objective sensory disturbances. Furthermore, improvement in the subjective sensory disturbances contributes to functional spinal cord recovery and patients' health-related QOL.