An 8-year old girl with chronic renal failure underwent allogeneic renal transplantation with implantation of the renal vein of the graft on the portal vein, as the inferior vena cava was obstructed by thrombosis. The possible technical obstacles to renal transplantation are reviewed on that occasion, and solutions are suggested. In the presence of thrombosis of the inferior vena cava it seems necessary to determine its level and to look for a patent venous segment all the way up to the diaphragm. If no such segment is found, then the renal vein can be implanted on the portal vein.