Medullar compression is an oncological and neurological emergency, whose diagnosis and early treatment are key factors for avoiding severe and irreversible neurological damage. Paralysis, loss of consciousness and alteration in control of the sphincters are the final consequence of the process, and represent an important source of morbidity of the oncology patient, besides being related to a shorter time of survival. The invasion of the vertebral body by haematogenous dissemination is the most frequent cause of medullar compression. On occasions it can create mechanical vertebral instability which represents a real orthopaedic emergency. Pain is the earliest and most frequent symptom. The signs and symptoms appear to the degree that the process advances, passing through motor weakness, alterations in consciousness until paralysis and incontinence of the sphincters are reached, as a result of complete neurological damage. Clinical history and physical exploration should lead to suspicion about the level at which medullar compression is developing, and the most important complementary exploration is MR of the entire spine, which should be requested immediately in order to decide on starting treatment. Treatment is individualised and must be started early. In general, corticoids in combination with radiotherapeutic oncological treatment and/or surgery are the therapeutic weapons to employ.