Chordoma is prone to local recurrence, distant metastasis is rare, and subdural metastasis is extremely rare. The patient was a 59-year-old female with blurred vision for one year, which was aggravated in one month and found in an outside hospital with left eyelid ptosis, left eye inversion disorder, diplopia, and diminished left facial pinprick sensation. The tumor was partially invaded into the subdural area, and the tumor was subtotally resected and pathologically diagnosed as chordoma. Two years later, the patient developed right eyelid ptosis, and the right parsaddle occupancy was found on repeat CT. On examination, he was found to have ptosis of the right eyelid, limited right eye movements in all directions, diplopia, shallow right nasolabial folds, right pupil dilatation with a diameter of 5 mm, direct and indirect light reflexes not elicited, grade III muscle strength of both lower limbs, and relaxed anal sphincter. Intraoperatively, old blood cerebrospinal fluid was seen in the subarachnoid space, and the tumor infiltrated the left lumbar 5 and sacral 2, respectively, and the right sacral 1 nerve root, and cystic changes and old hemorrhage were seen in the section. The left sacral 2 nerve root could not be separated and was resected together with the tumor. The remaining tumor was resected after separation of the nerve and the pathological diagnosis of chordoma was made. After surgery, the pain was relieved and the muscle strength of the lower limbs was grade IV, but there was no significant improvement in the difficulty in urination and defecation. He was transferred to an outside hospital for further radiotherapy. Discussion Chordoma is rare [1], and subdural dissemination of metastases is rarely reported, so its exact incidence cannot be estimated. Chordomas are generally slow-growing, have an older age of onset [1], slope chordomas often involve the brainstem, have a poor long-term prognosis, and some patients with subdural dissemination may die before they develop symptoms, so their incidence may be higher than currently reported. This is supported by the fact that some subdural dissemination is only an incidental finding. Bulk autopsy studies may help to understand its incidence. Slope chordoma has a tendency to implant metastases [2] and subdural dissemination is the result of intraoperative tumor cell implantation, but subdural dissemination can also occur in patients who have not undergone surgery [3]. Nevertheless, we believe that the dura should be kept as intact as possible intraoperatively, and special attention should be paid to prevent tumor cell dissemination when the dura must be opened [4]. The literature reports that subdural dissemination of skull base chordoma occurs from 7 months to 11 years after surgery [4], and in this patient it occurred 6 years after surgery. This may be related to slow tumor growth, but this patient was accompanied by rapid intracranial tumor enlargement and metastasis, which may be related to tumor malignancy due to γ-knife treatment, for example [4, 5]. In contrast, the malignancy of chordoma may be associated with changes in the expression of the calcineurin-chain protein complex, i.e., downregulation of E-calcineurin and increase in N-calcineurin [6]. This patient had postoperative pain relief and improved muscle strength, but poor recovery of diastolic function. Early detection and treatment may improve the patient’s prognosis. Regular MRI of the spine in patients with intracranial chordoma helps in early detection and improves the patient’s prognosis, but increases the burden on the patient [7]. Subdural dissemination of intracranial chordoma is rare, but spinal MRI should be performed promptly to understand the presence of metastases when patients present with spinal cord or nerve root symptoms.