There is an ever-increasing gap between the number of donors and those waiting for organ grafts, resulting in increased waiting times and mortality on transplant waiting lists. Consequently, every potential donor must be considered for possible transplantation even if they are outside the conventional donor criteria. To address this imbalance, organs are currently transplanted from living donors, older donors, haemodynamically unstable and non-heart-beating donors, and donors with prior infections. There is a potential to transmit infections and, to a lesser extent, malignancy from the donor organ to the immunosuppressed recipient, and this may also have an effect on subsequent organ function in the recipient. Thus, transmission of infections from organ donors to recipients represents low but serious potential risks that must be weighed against a candidate's risk of dying before a transplant becomes available.