Nephrogenic systemic fibrosis is a progressive, potentially fatal multiorgan system fibrosing disease related to exposure of patients with renal failure to the gadolinium-based contrast agents used in magnetic resonance imaging. Because of this relationship between nephrogenic systemic fibrosis and gadolinium-based contrast agents, the U.S. Food and Drug Administration currently warns against using gadolinium-based contrast agents in patients with a glomerular filtration rate less than 30 mL per minute per 1.73 m2, or any acute renal insufficiency related to the hepatorenal syndrome or perioperative liver transplantation. There have been reports of nephrogenic systemic fibrosis developing in patients not exposed to gadolinium-based contrast agents, but most patients have the triad of gadolinium exposure through contrast-enhanced magnetic resonance imaging, renal failure, and a proinflammatory state, such as recent surgery, endovascular injury, or sepsis. Development of nephrogenic systemic fibrosis among patients with severe renal insufficiency following exposure to gadolinium-based contrast agents is approximately 4 percent, and mortality can approach 31 percent. The mechanism for nephrogenic systemic fibrosis is unclear, and current treatments are disappointing. Prevention with hemodialysis immediately following gadolinium-based contrast agents has been recommended, but no studies have shown this to be effective. Because of the large number of patients with clinically silent renal impairment and the serious consequences of nephrogenic systemic fibrosis related to gadolinium exposure, physicians should use alternative imaging modalities for patients who are at risk.