Mature teratoma of the vermis is a rare entity in neurosurgical adulthood pathology. We present the case of a 65 years old patient, admited as an emergency for intense headache (VAS 8/10), nausea, vomiting, gait ataxia, orizontal nistagmus, dismetria, disdiadocokinezia, predominant on the left side, long tracts signs, predominant on the left side. Native and contrast CT and MRI scan of the head revealed a tumoral lesion, in the vermian, paravermian and in the fourth ventricle, with the aspect of a teratoma with intratumoral subacute haemorrhage including a giant lesion 5,5/5/4,5 cm, compressive on mesencephalon, and with suprajacent acute internal hidrocephalus. Emergency neurosurgery was performed (occipital infratentorial craniectomy, microneurosurgical total tumoral resection and haematoma evacuation). Postoperative, the patient recovered progressivelly , subtotal neo and arhicerebellar symptoms. The motor long tract signs recovered slower and persisted incomplete.