Objective: Diazoxide (DZ) has been shown as an effective pharmacological ischemic preconditioning agent. In a previous report, we showed that DZ had a strong protection of rodent islets against ischemia-reperfusion injury. In this follow-up study, we are investigating whether DZ supplementation to University of Wisconsin (UW) solution during pancreas harvesting and preservation has similar cytoprotection in non-human primate. Research Design and Methods: Cynomolgus monkey pancreata were flushed with UW (n = 3) or UW + 150 μM DZ (n = 3) during pancreas harvesting and preserved for 8 hrs prior to islet isolation. Islet yields, in vitro, and in vivo function were evaluated. Results: (i) Significantly higher islet yields were observed in the UW+DZ group than in the UW group (5,7887 vs. 23,574 IEq/pancreas; p = 0.02. and 5,396 vs. 1,646 IEq/gram; p = 0.019). (ii) The DZ-treated islets had higher insulin content (59.22 vs. 40.35 ng/islet; p = 0.006). The islets from the UW + DZ group post culture have significantly higher insulin positive cells per islet (96.15% vs. 82.74%; p = 0.004). (iv)The DZ-treated islets had a significant lower apoptotic cells per islet post culture (1.64% vs. 9.85%, p = 0.0015). (v) The DZ-treated islets had improved in vitro calcium influx in response to glucose challenge and in vivo function reflected in a higher cure rate and shorter days needed to reverse diabetes in a nude mouse transplant model. Conclusion: This study in NHP confirmed our previous observation in rodent model, showing similar DZ cellular protection on islet cells against ischemia-reperfusion injury that provides a strong evidence for future DZ application in human islet and pancreas transplantation.