Myelopathy caused by vitamin B12 deficiency is an uncommon entity, because a long period of time must pass in order to appear its signs and symptoms and for the structural lesion to be irreversible. We present a case of a patient with signs and symptoms suggestive of Subacute Combined Degeneration of the Spinal Cord secondary to autoimmune gastritis with a persistent lesion in the posterior columns of the spinal cord as sequelae. The literature about the topic is reviewed.