We examine with phlebography usually a damaged vascular system. Radio-contrastmedia damage vascular endothelium. If we dilute them we may minimize the damaging effect. But when using the usual film-foliae combination, diagnostic results diminish the more we dilute. Results of 31 comparative investigations with film and xerphlebography show that dilution of contrast medium to 50 or even 25% will still produce phlebograms sufficient for evaluation with xerophlebography. It also has the advantage of a large picture: soft parts, veins and bony structures are visible of the same time. At present the method (chance of screening, gaps) renders routine use not advisable.