Radiocontrast-induced nephropathy causes significant morbidity and mortality with increase in hospital length of stay and costs. It can be largely prevented by identifying the patients at risk before the procedure. Once the at-risk patient is identified, ways to prevent the development of acute renal failure are: avoiding volume depletion, aggressive saline hydration with the aim of keeping the urine output over 150 mL/hour, and the use of low-osmolality contrast agents, with as little volume used as possible. There is theoretical potential for the dopamine DA1 agonist fenoldopam as a preventive agent, and this is currently being tested in randomized trials.