In our study 13 patients with a Klippel-Trenaunay type and 7 patients with a Servelle-Martorell type of arteriovenous malformations were analyzed. The results demonstrate that these 2 entities can be differentiated by routine radiography. The Klippel-Trenaunay type of angiodysplasia does not need arteriography, whereas arteriography as well as phlebography are necessary in the Servelle-Martorell type of angiodysplasia, in order to show ectatic regions of the involved vessels. The differentiation between the above mentioned arteriovenous malformations and the F. P. Weber type of angiodysplasia is easy. In the F. P. Weber type of angiodysplasia a lengthening of the involved extremity, arteriovenous shunts, as well as alterations of the bone are characteristic.