We have tested a protocol that uses a new cryoprotective solution for preserving mammalian livers in a frozen state. This protocol is based upon our studies on the mechanisms that freeze tolerant animals use to survive freezing in nature. The cryoprotective solution contains glycerol and antifreeze proteins, both of which are found in freeze tolerant animals. Whole rat livers were frozen to -3 degrees C, maintained at that temperature for 6 hours and then warmed to 37 degrees C. Post thawing bile production and microscopic analysis of tissue slices were used to verify liver function and tissue morphology. We conclude that antifreeze proteins used in the concentrations chosen here have a protective effect on the whole liver during freezing.