Contrast media-associated nephrotoxicity (CM-AN) continues to be a common cause of hospital-acquired acute renal failure. This review of CM-AN discusses the pathogenesis, clinical features, incidence, risk factors with an emphasis on pre-existing renal insufficiency and diabetes mellitus, volume of contrast media, low osmolar versus high osmolar contrast media, and prophylaxis. Although the literature contains an abundance of information concerning CM-AN, areas of uncertainty remain in respect to clinical significance, risk with modem day radiological techniques and contrast media, optimal prophylactic regimens, and criteria for creatinine screening before contrast media administration.