Maintaining organ viability from extraction to transplantation is crucial to ensure the function and survival of the graft. In recent years, maintaining organ viability has become more challenging because the shortage of donors has led to broader criteria for donor acceptability and consequently to organs with greater compromise. Organ damage occurs primarily as a result of ischemia-reperfusion injury, which is associated to additional damage from the preservation process. To minimize this damage, different techniques of organ preservation are used with the aim of optimizing organ function once perfusion is restored. Static cold storage is the most commonly used method of preservation because it is extremely simple, nearly universally available, and easy to transport. However, static cold storage may be unable to prevent the deterioration of the quality of organs from donors included under the broader criteria. In this article, we describe current preservation techniques; we place special emphasis on continuous machine perfusion.