Transosseous vertebral venography as a technic for investigating disease of the lumbosacral region is described. The technic preferred by the author is an intraosseous injection of contrast medium into the body of L7. Using a caudal needle, 10 ml of contrast medium was injected manually and a radiograph was made as the last milliliter was introduced. Contrast medium filled the lumbar venous sinuses and, by reflux, filled the sacral sinuses caudally to the S2–3 intervertebral foramen. Lumbosacral disease caused an obstruction to contrast medium flow and narrowed or deviated the vertebral venous sinus. Complications of transosseous vertebral venography were extravasation of contrast medium into the epidural space and surrounding soft tissue, and trauma to the sixth lumbar nerve in one dog. The procedure was contraindicated in the presence of local infection and when anesthesia was an undue risk.