The use of diagnostic and therapeutic catheterization is increasing and so is the exposure to radiocontrast media. As a consequence, an increasing incidence of contrast media-associated nephropathy is being observed. This article reviews pathogenesis, clinical symptoms and preventive measures of contrast media-associated nephropathy. Most important prophylactic measures is identification of high-risk patients, careful selection to be exposed to contrast media, application of non-ionic low osmolality or -- most recently -- iso-osmolality contrast media, adjusted hydration with isotonic saline before/during catheter interventions, and potentially the administration of acetylcysteine.