Iron overload is the histologic hallmark of hereditary hemochromatosis and transfusional hemosiderosis but also may occur in chronic hepatopathies. This article provides an overview of iron deposition and diseases where liver iron overload is clinically relevant. Next, this article reviews why quantitative noninvasive biomarkers of liver iron would be beneficial. Finally, we describe current state-of-the-art methods for quantifying iron with MR imaging and review remaining challenges and unsolved problems. Copyright © 2010 Elsevier Inc. All rights reserved.