Contrast-induced nephropathy (CIN) is a fairly common yet under-recognized clinical condition in the interventional cardiological practice. A 25% or more than 0.5 mg/dl rise of serum creatinine is generally accepted as defining CIN. The most important risk factors for CIN are pre-existing renal disease, volume of contrast media, nature of contrast media, and diabetes mellitus. Among the various postulated pathophysiological mechanisms for the precipitation of CIN, intra-renal vasoconstriction, and oxidative tubular injury are the best documented. Effective strategies to prevent CIN include adequate peri-procedural hydration with normal saline, use of N-acetylcysteine, keeping the volume of contrast media as low as feasible, and avoiding high-osmolal ionic contrast media. However, more efficient and cost-effective strategies are being developed and the search for the ideal contrast media is still on.