of renal function that usually occurs 48‑72 hours after the administration of the contrast agent, is much more common than previously thought. In most cases, the clinical course of acute renal failure is mild and transient, but it has been proved that even a subtle impairment of renal function causes severe clinical consequences in the future. The difficulties in diagnosis of CIN is further aggravated by the fact that the kidney damage caused by contrast agent administration usually takes place without obvious clinical symptoms and oliguria. Current researches focus on improving the diagnostic process and try to develop effective prophylactic protocols. The increase in serum creatinine concentration is relatively late indicator of acute kidney injury thus more useful markers are being investigated. High expectations are given by clinical use of cystatin C, NGAL and interleukin 18. Many publications are focused on attempts of identifying risk factors of contrast‑induced nephropathy. It is already known that a very careful intravascular contrast administration is needed in case of patients with chronic renal disease or diabetes mellitus. Procedure dependable risk factors are as following: a type and dose of contrast agent, a method of contrast administration or repeatability of the procedure in a short period of time. The highest prophylactic value has an adequate hydration of the patient, moreover, N‑acetylcysteine has been found as the most promising pharmacological agent.