Over a period of seven years nine patients with vascular complications after lumber discectomy received medical care at the Clinic of Vascular Surgery, University of Graz Medical School. We report five acute bleeding complications occurring during the operation and four late manifestations of vascular lesions. Five patients presented with acute life-threatening iatrogenic haemorrhages from pelvic vessels. Three patients made a complete recovery, one patient died from acute haemorrhagic shock, one further patient died from sepsis due to an associated complication-an injury to the ureter. Over a period of two to ten years after primary surgery we corrected late complications such as 1 case of posttraumatic aneurysm of the aortic bifurcation found to have eroded the body of the fifth lumbar vertebra, and three cases of arteriovenous fistula between the common iliac artery and the common iliac vein. The four cases described below are an attempt to document the vascular surgical procedures involved and to provide typical findings. The risk of injuring the pelvic vessels intra-operatively can be explained by the close anatomical relation between the retroperitoneal vessels and the vertebral column and furthermore not only by the fact that pre-existent deficiencies but also injury to the anterior longitudinal ligament give access to the retroperitoneal space.