In patients with renal disease a reduced renal vasodilatory but conserved natriuretic response to dopamine is observed. An inverse relationship exists between baseline renal function and the dopamine-induced changes in effective renal plasma flow and glomerular filtration rate over a wide range of dopamine doses. The renal hemodynamic response to dopamine is also impaired in kidney donors. In studies with dopamine antagonists and in measurements of urinary free dopamine excretion no evidence was found for increased endogenous renal dopamine generation in these patients. The response of effective renal plasma flow and filtration fraction to fenoldopam was also impaired. However, the fractional sodium excretion in patients with renal disease was not impaired in both short-term and long-term studies. Perhaps this conserved natriuretic effect is of clinical value in these patients.