We report a 37-year-old female patient who had progressive right foot weakness for 5 years and drop foot developed in the recent 2 years. Spinal angiographies revealed a conus medullaris arteriovenous malformation fed by the right L1 and L4 radiculopial arteries and direct arteriovenous fistulae fed by the left T12 and L1 radiculopial arteries. A large distorted right L5 great radicular vein drained along the cauda equina from the L1 to the L5 level. The distended venous varices compressing the right L5 and S1 nerve roots resulted in right foot palsy.