Over a 16 month period seven patients underwent surgery using venous allografts either to reconstruct the portal vein, or to construct a mesocaval 'H' graft or a shunt between the coronary vein and the subhepatic inferior vena cava. The allografts were harvested during multiorgan procurement from the bifurcation of the inferior vena cava, the common iliac vein and the external iliac vein and kept in a preservation solution at 4 degrees C for a mean time of 6 days (range 1-29) before use. Subsequent thrombosis was clinically evident in only two patients. The use of venous allografts appears to be a useful alternative to other venous replacements.