Kidney degradation during hypothermic storage was studied on rat kidneys, using magnetic resonance microscopy. Poor storage, modeled by storage with lactated Ringer's solution, resulted in rapid kidney swelling, together with increased signal intensity and water diffusion coefficient in the cortical and medullary regions. Storage of kidneys in Euro-Collins solution resulted in slower swelling and no significant change in signal intensity and in the water diffusion coefficient. Storage with Belzer's solution resulted in shrinkage of the kidneys and no significant change in the diffusion coefficient of water over time. These changes correlated well with kidney degradation observed by histology, and show the potential of magnetic resonance imaging in quality assessment of kidney transplants.