Five cases in which the Klippel-Trenaunay-Weber syndrome was associated with a spinal cord arteriovenous malformation are reported: they formed part of a series of 150 spinal arteriovenous malformations. Hypertrophic lesions, dilated arteries and varicose veins were present in every case, but cutaneous angiomatosis was found in only two. In each case, there was an intramedullary AVM. The relationship of the Klippel-Trenaunay-Weber syndrome to the regional angiomatous phacomatoses is discussed.