About three and a half years ago, a causal relation between nephrogenic systemic fibrosis (NSF) and exposure to gadolinium based contrast agents (Gd-CAs) was suggested. All evidence now suggests that low stability Gd-CAs can trigger the development of NSF. All studies indicate with no exception that macrocyclic Gd-CAs release significantly less free gadolinium than the linear agents, particularly the non-ionic ones which have the highest potential of gadolinium release. The longer the Gd-CA stays in the body the larger the amount of gadolinium that is retained in the body. The magnitude of the NSF problem remains uncertain; the condition seems to be underreported. The demonstration of a link between NSF and low stability Gd-CAs has had major consequences for patients with reduced renal function. Currently, if contrast administration is clinically deemed; necessary the preferred approach is contrast enhanced MRI using a macrocyclic Gd-CA. Contrast enhanced CT is at least as risky if not more as an enhanced MRI with low stability Gd-CAs.