The successful outcome of the majority of corneal transplants depends on the presence of a viable corneal endothelium. This monolayer of cells lines the inner surface of the cornea and its primary function is to maintain corneal transparency by controlling the hydration of the collagenous stromal layer. Since human corneal endothelial cells do not readily proliferate, preservation of the endothelium is a primary aim of methods of corneal storage. Although some cryopreserved corneas have been transplanted successfully, the complexity of the cryopreservation technique and its potential for causing endothelial damage have limited its application. Hypothermia (2–8°C) is the most commonly applied method of storage, which allows storage for 7–14 days. Organ culture (28–37°C), which extends storage time to 4 weeks, is used widely in European eye banks. Graft outcomes for corneas stored by these two techniques appear similar.