Contrast-induced nephropathy (CIN) is the third leading cause of hospital-acquired acute renal failure (ARF). Accounting for 12% of ARF cases, CIN is defined as an increase of serum creatinine of at least 0.5 mg/d (“Barrett´s definition”) and/or 25% within 48 hours of contrast-medium application. CIN is associated with prolonged hospitalisation and increased mortality. CIN frequency depends on several risk-factors including pre-existing renal dysfunction, high amounts of contrast-medium, diabetes, and concurrent use of nephrotoxic drugs. CIN incidence is low in the absence of risk-factors; however, in high-risk patients, CIN occurs in more than 50% of patients.