The best treatment for end-stage renal disease is the transplantation of a live donor kidney, but many people cannot donate to their loved ones because they are incompatible. Kidney exchange promises relief. Kidney exchange programmes use centralised procedures to match donors with recipients in a way that maximises the quantity and quality of transplants. However, the transplant laws in many countries render kidney exchange programmes impossible because of ethical concerns against these programmes or against kinds of kidney donations on which these programmes rely. I give two novel arguments for the implementation of kidney exchange programmes. The first is that they are instrumental in meeting a moral obligation, namely to donate effectively. The second is that they may increase the motivation for altruistic donations, because the donation of one kidney may trigger >1 life savings. Moreover, ethical concerns are considered that are embodied in transplant laws preventing the implementation of kidney exchange, and it is argued that they can be overcome.