The spinal dural arteriovenous fistula (SDAVF) is an important cause of a slowly progressive sensorimotor transverse lesion in mostly elderly patients. The disease affects men in 80% of the cases. Per year and per 1 Million inhabitants only 5-10 new cases of the disease have to be expected. Although rare, the serious disease should not be missed. Diagnosis can be made by MRI and spinal angiography. The result of treatment depends on early diagnosis. The arteriovenous shunt is located within the dural layer of the spinal canal. It connects branches of a radiculomeningeal artery with the veins of the spinal cord. Spinal cord supplying vessels are not primarily involved. Arterialisation of the venous part of the spinal cord circulation results in a chronic congestive myelopathy, which can well be demonstrated by MR imaging. The role of selectice spinal angiography is to detect and exactly localize the site of the avshunt, which is rather difficult in some cases. Therapeutic alternatives are effective embolization of the fistula with liquid agents or surgical disconnection.