AbstractContrast induced nephropathy (CIN) is an iatrogenic disorder, resulting from exposure to contrast media. Contrast‐induced hemodynamic and direct cytotoxic effects on renal structures are highly evident in its pathogenesis, whereas other mechanisms are still poorly understood. CIN is typically defined as an increase in serum creatinine by either ≥0.5 mg/dl or by ≥25% from baseline within the first 2–3 days after contrast administration. Although rare in the general population, CIN has a high incidence in patients with an underlying renal disorder, in diabetics, and the elderly. The risk factors are synergistic in their ability to produce CIN. The best way to prevent CIN is to identify the patients at risk and to provide adequate peri‐procedural hydration. The role of various drugs in prevention of CIN is still controversial and warrants future studies. Despite remaining uncertainty regarding the degree of nephrotoxicity produced by various contrast agents, in current practice non‐ionic low‐osmolar contrast media are preferred over the high‐osmolar contrast media in patients with renal impairment. © 2007 Wiley‐Liss, Inc.