The authors report the case of a 30-year-old man who presented with progressive neurological deficits due to a spinal arteriovenous malformation (AVM). There was sudden increase in his neurological deficits after diagnostic angiography was performed. Repeated magnetic resonance imaging and angiography revealed complete thrombosis of the malformation. Stenosis in the draining vein was the most probable cause of this postangiographic occlusion of the AVM. Contrast injection during angiography may have precipitated the thrombosis.