Recurrent vasculitis and vein thrombosis, including involvement of the superior vena cava, are serious complications of Behcet's disease, and may present an obstacle during implantation of permanent endocardial transvenous pacemaker and/or automatic defibrillator. Six male patients, known to suffer from Behcet's disease, who required pacemaker and/or defibrillator therapy were investigated. Both invasive (phlebography) and non-invasive (echo-Doppler and isotopic angiography) vascular imaging techniques were available. In one patient, total occlusion of the upper thoracic veins was demonstrated by angiography. In a second patient, following implanted defibrillator, partial left subclavian vein obstruction was demonstrated by the two noninvasive methods. In the remaining four patients, patency of the upper thoracic veins was demonstrated, prior to and following pacemaker implantation, by the two nonin-vasive methods, with a good correlation. As echo-Doppler or isotopic angiography are widely available, easy to perform and reproducible, it is suggested that upper thoracic vein patency in patients with Behcet's disease should be evaluated prior to and following such vascular procedure, by one of these methods, in order to prevent unnecessary attempts to cannulate obstructed or stenosed vessels.