The discrepancy between the number of patients awaiting liver transplantation and the number of available donors has become a key issue in the transplant setting. Various strategies to cope with the donor shortage problem and to increase the use of suboptimal grafts have been explored. Machine perfusion has been applied ex situ to liver grafts in the effort to improve static cold-storage preservation. If a more extensive application of this technology confirms the preliminary results, machine perfusion will become crucial in increasing the donor pool as well as improving recipients’ outcomes. In this review, the authors focused on the evolution of machine perfusion, from the first animal experiences to the latest evidence in humans, highlighting the pros and cons as well as the potential clinical applications of various types of machine.