Posterior migration of spinal cord is a common complication of posterior cervical decompression, whereas anterior migration of spinal cord after anterior cervical decompression has not been reported previously. This report presents a case of anterior migration of spinal cord after cervical corpectomy. A 65-year-old male underwent a cervical corpectomy of the C4 and C5 for cervical spondylotic myelopathy. The postoperative MRI showed that spinal cord was decompressed. However, at 12 months postoperatively, the patient complained that improved gait aggravated again, and the MRI showed an anterior migration of the spinal cord at the level of the C4 and C5, and a compression of spinal cord at the level of caudal endplate of C3. Secondary surgery, laminaplasty of C3 and C4 was conducted. The postoperative MRI showed that the spinal canal increased at the C3 and C4 levels, and the spinal cord went through smoothly without sharp turning.