A 29-year-old man with Klippel-Trenaunay syndrome (KTS) presented with a symptomatic conus medullaris-cauda arteriovenous malformation (AVM) manifesting as back and right limb pain, which abruptly worsened with the onset of right limb weakness and urinary retention. He was treated by multisession endovascular embolization resulting in improved neurological status. KTS is a sporadic disease with unknown etiology, but genetic susceptibility may lead to the over-expression of angiogenic factors and increased angiogenesis. KTS may be exceptionally associated with slow-flow spinal AVM, but there is no consensus about the optimal treatment for these symptomatic lesions. Embolization treatment may represent a safe option to minimize complications and possibly improve the neurological status in patients with spinal AVM associated with KTS, if one or both legs are already impaired by hypertrophy or other vascular malformations. Genetic analysis may reveal an underlying angiogenesis change, so closer follow up might be indicated in selected patients.