Allogenous venous umbilical implants can be used for successful vascular reconstructions and for the establishment of dialysis shunts. Presently 15 patients were treated with venous umbilical implants, in two of which a thrombosis of the implant occurred, one of them showed slight dilatation. In the case of dialysis shunts, implants serve exceptionally well. Especially the fixation in formalin can be especially recommended for preservation due to the fact that the umbilical veins can be obtained under non-sterile conditions, the immunological rejections are omitted. According to the present observations the mechanical properties are favourably influenced. At the time of the operation the umbilical veins do not possess an endothelium, nevertheless their functions are thereby affected. The results up to present time are favourable, nevertheless further investigations are necessitated.