Objective: The aim of this study was to compare the outcomes of simultaneous and delayed implantation of kidney grafts in combined liver-kidney transplantation (CLKT). Background Data: Delayed function of the renal graft (DGF), which can result from hypotension and pressor use related to the liver transplantation (LT), may cause worse outcomes in CLKT. Methods: A total of 130 CLKTs were performed at Indiana University between 2002 and 2015 and studied in an observational cohort study. All kidneys underwent continuous hypothermic pulsatile machine perfusion until transplant: 69 with simultaneous kidney transplantation (KT) (at time of LT, group 1) and 61 with delayed KT (performed at a later time as a second operation, group 2). All patients received continuous veno-venous hemodialysis during the LT. Propensity score match analysis in a 1: 1 case-match was performed. Results: Mean kidney cold ischemia time was 10 +/-3 and 50 +/-15 hours, for groups 1 and 2 (P48 hours (P48 h) is associated with improved kidney function with no DGF post-KT, and improved patient and graft survival.