Hyperpolarized noble gases are a new class of MR contrast agent. Since the first hyperpolarized gas MR images of the lung were reported, there has been considerable interest in using hyperpolarized gas to obtain high spatial and temporal resolution images of the air spaces of the lung. In addition to static images of lung ventilation, new techniques are being developed using hyperpolarized gas to obtain dynamic, diffusion and oxygen concentration images of the lung. In this article, we review the potential clinical applications of pulmonary hyperpolarized gas MRI and discuss the preliminary findings in a variety of lung diseases. Hyperpolarized gas MRI has the potential to provide a comprehensive morphologic and functional assessment of the lung.