Nephrogenic system fibrosis is a rare disease affecting patients with severe renal insufficiency or dialysis. Its aetiology is incompletely understood. Evidence is growing that gadolinium contrast media is a major risk factor, whereby risk increases with larger cumulative doses. The role of other risk factors, such as inflammation or electrolyte disturbances, is less clear. All published cases to date received gadodiamide, gadopentetate or gadoversetamide, which are considered to be less stable due to a linear molecular structure. The aetiological significance of stability differences between the non-ionic linear, ionic linear and macrocyclic agents remains to be shown. For prevention, strict indications for MRI in risk patients can be combined with Food and Drug Administration (FDA) or European Medicines Agency (EMEA) guidelines. These recommend checking for renal impairment by history or laboratory tests. The FDA recommends avoidance of all gadolinium contrast media in patients with renal insufficiency grades 4 and 5 (glomerular filtration rate <30 mL/min per 1.73 m(2)) or any grade of acute renal failure in liver transplantation patients or candidates. The EMEA differentiates between agents and advises avoidance of only gadodiamide and gadopentetate in the same patient categories. Other gadolinium contrast media should only be used after careful consideration of risks versus benefits. Post-procedural haemodialysis is only indicated in patients on regular dialysis.