The physiologic and morphologic effects of total en bloc spondylectomy (TES) on spinal cord circulation in cats were studied by spinal cord blood flow (SCBF) and examined with microangiogram and scanning corrosion casts. SCBF decreased significantly following laminectomy (average 22.1%), while circumspinal decompression produced no further decrease. Ligation of the Adamkiewicz artery decreased SCBF only by 19.0% in average and caused no conduction disturbance electrophysiologically. TES on the vertebra at the level of the Adamkiewicz artery produced no morphologic changes in spinal cord vessels and self-regulation of blood flow was also preserved. These findings indicate that total en bloc spondylectomy on one vertebra has little effect on spinal cord circulation.