Dorsal thoracic arachnoid web is a rare but often overlooked cause of progressive myelopathy. Syringomyelia, either above or below the compressive arachnoid band, may also be present. Dorsal arachnoid cyst and ventral spinal cord herniation may be mistaken for this condition. This video demonstrates the microsurgical identification and techniques of resection of a dorsal arachnoid band producing a progressive myelopathy in a 63-year-old man. The video can be found here: http://youtu.be/KDNTqiyW6yo 1).