Kidney and pancreas transplantation have helped transform the lives of people with end-stage renal failure and individuals with type 1 diabetes who have poor glycaemic control/severe secondary complications, respectively. Despite an improvement in immunosuppressive regimes, operative techniques and decreased initial rejection rates, there has been little improvement in long-term graft survival rates over the past decade. Whilst limited progress has been made in establishing clinical markers of graft function, several genetic markers of long-term graft function have been identified. These genetic markers have the potential to (i) assist in selecting marginal donor organs for transplantation, (ii) provide better understanding of the mechanisms behind graft loss enabling identification of new, or repurposing, current treatments to extend graft function and (iii) provide a window of opportunity to identify and treat individuals before graft failure has occurred. This review will discuss the different genetic variants screened for a role in predicting transplant longevity, examine their findings and limitations and introduce where the future of genetic research within the transplantation field lies.