Expansive laminoplasty is a new technique for the management of cervical ossification of the posterior longitudinal ligament (OPLL). Twenty patients were followed up for an average 3-year period. Follow-up examinations were performed every 3 months and at 1-year intervals. On lateral radiographs, the average increase in the anteroposterior (AP) diameter of the canal was 42%. Bone fusion was documented on computed tomography (CT) studies 3 months after surgery in 96% of patients. An average 83% of normal range of motion was preserved on long-term follow-up (3 years on average). Postoperative improvement over the same interval increased from an average preoperative Japanese Orthopaedic Association score of 7.9 to 14.1 Expansive laminoplasty as described is safe and has a high fusion rate, while better preserving the normal range of motion.