A 22-year-old woman with congenital afibrinogenemia presented with acute-onset rapidly progressive quadriparesis as a result of spinal cord infarction caused by vertebral artery dissection. Magnetic resonance imaging scans showed microhemorrhages in addition to edematous swelling suggesting acute ischemia throughout cervical and upper thoracic portions of the spinal cord. Fat-saturated T1-weighted magnetic resonance examination and digital subtraction angiography studies demonstrated cervical vertebral artery dissection on the right. This case provides an example of how a primary bleeding disorder could result in a severe ischemic complication caused by an occlusive vessel wall hematoma. Along with other reports, diagnostic and therapeutic aspects of this paradoxical situation were discussed in the particular setting of acute spinal cord ischemia.