The definitive diagnosis of renal vein thrombosis (RVT) depends upon the demonstration of a persistent filling defect or defects within the renal vein by renal venography or selective renal angiography during the venous phase. We describe here the utilization of digital subtraction venography to diagnose RVT in a young nephrotic male patient. We injected 40 cm3 of contrast substance in a foot vein, having 4-second delayed films over the inferior vena cava and renal veins. We demonstrated a retrograde propagation of the dye into the right renal vein indicating intrarenal venous thrombosis. ‘Renal vein thrombosis and digital venography