125I-Hippuran renography was performed after temporary renal arterial clamping in contralateral nephrectomized rabbits. Mean renograms for the experimenttal groups were calculated for 0, 1, 1 1/2, 2, 2 1/2 and 3 h of warm ischaemia. The appearance phase, the 1 min uptake phase and excretion ratio were evaluated. The kidney function was monitored by serum-creatinine. Warm ischaemia of 1, 1 1/2 and 2 h resulted in a late maximum peak and delayed excretion, and for the last group in an accumulation curve. The uptake capacity was normal for these groups. Protracted ischaemia of 2 1/2 and 3 h affected also the appearance and uptake phase resulting in a slower and decreased Hippuran uptake of 50% and 34% respectively. Duration of warm ischaemia and changes in the renogram were well correlated. A normal uptake phase predicts restitution of the kidney function and 100% survival.