OBJECTIVE: Unexpected donation after cardiac death (DCD) donors suffer cardiac arrest suddenly and are maintained with normothermic extracorporeal membrane oxygenation (NECMO) while consent for donation is obtained. The objective of this study was to determine whether ex vivo normothermic machine perfusion (NMP) improves upon the benefits of NECMO in a large-animal model of unexpected DCD liver transplant. METHODS: Donor pigs underwent 90-minute cardiac arrest and were divided in to 3 groups. In the first, livers were preserved immediately with cold storage (CS, n = 6). In the other 2 groups, donors underwent 60-minute NECMO followed by CS (NECMO+CS, n = 6) or NMP (NECMO+NMP, n = 6). After 4-hour preservation, livers were transplanted into recipient pigs. RESULTS: Five-day survival was 0 in CS, 83% in NECMO+CS, and 100% in NECMO+NMP. After reperfusion, injury, and inflammatory markers rose significantly among CS grafts, all of which developed primary nonfunction. Sixty minutes of NECMO, however, resulted in only 1 death, whereas NECMO followed by NMP led to no deaths and significant improvements in injury, inflammation, and synthetic function in comparison to NECMO and CS. CONCLUSION: Although 60 minutes recuperative NECMO is better than CS alone, NMP improves further on NECMO and may have a role in preserving DCD livers in the clinical setting.