Into 24 oliguric patients with acute renal failure (ARF) for whom mannitol and high-dose frusemide had failed to promote a diuresis, dopamine (3 μg/kg/min) plus frusemide (10–15 mg/kg/h) were infused for 6–24 h. In 19 of the 24 patients this treatment produced significant increases in diuresis (from 11 ± 7 to 85 ± 51 ml/h; p < 0.001) and natriuresis (from 45 ± 13 to 88 ± 22 mEq/l; p < 0.001), without any significant modification of blood pressure, pulse rate or central venous pressure. 10 of the 24 patients required dialysis: 5 because therapy failed to promote diuresis and the other 5 because of their hypercatabolic state in spite of polyuria. 5 patients died of causes unrelated to ARF. Since all patients who responded were treated within 24 h after the onset of oliguria, it appears to be crucial to administer dopamine and frusemide early, before more severe anatomical and functional damage