Background: Dialysis prior to kidney transplantation may have a detrimental effect on post-transplant outcomes. Methods: A retrospective cohort study was conducted in all deceased-donor kidney transplants performed in Ontario, Canada from April 1, 2002 to March 31, 2013. Patient blood type was chosen as an instrumental variable and a two-stage modelling procedure was conducted. Result: Among 4,728 patients, the risk of death increased non-linearly with dialysis time and was more prominent during the earlier years. Each dialysis year prior to 3 (3.05) years was associated with a 42% increase in the relative hazard of death. The relative hazard fell to 5% per additional dialysis year thereafter. Conclusions: Longer dialysis time leads to a non-linear increase in mortality risk after kidney transplantation. These findings highlight the urgency to develop strategies to shorten waiting times and optimize the management of wait-listed patients.