Nephrogenic systemic fibrosis is a devastating systemic fibrosing disorder that afflicts patients with renal dysfunction. Growing evidence supports the hypothesis that gadolinium-containing contrast agents (GCCAs) trigger the development of nephrogenic systemic fibrosis. Hence, this condition is most appropriately called gadolinium---associated systemic fibrosis (GASF). In this report, we review the history of GASF, its association with prior GCCA exposure, its clinicopathologic features, the relevant pharmacology of GCCAs, the likely role of GCCAs in its pathogenesis, and potential treatments.