Two patients are described who acquired neonatal flaccid paraplegia associated with umbilical artery catheterization. Neurophysiologic studies demonstrated spinal cord injury at the level of T7 and below in Patient 1 and at the level of L1 and below in Patient 2. Deferred spinal cord magnetic resonance imaging confirmed regional spinal cord atrophy. In Patient 1, the syndrome was presumed to be triggered by a spasm or embolism of the Adamkiewicz artery due to movement of the umbilical artery catheter. In Patient 2, the spinal cord ischemia was probably caused by an embolic mechanism.