© 2020 Elsevier B.V. Guy Alexandre made major contributions to organ transplantation that, in my opinion, have not been sufficiently recognized by the transplant community. To make his contributions better known, I present a brief summary of the innovations for which he was largely responsible. As a research fellow at the Peter Bent Brigham Hospital in Boston in 1962–3, under subsequent Nobelist Joseph Murray, he contributed to the establishment of pharmacologic immunosuppressive therapy (initiated by Roy Calne) in patients undergoing renal allotransplantation. After his return to his native Belgium, he carried out the first clinical kidney transplant there and, controversially, was the first to take kidneys from brain-dead donors (in 1963), a major advance in organ transplantation. He was also the first to carry out an elective series of kidney transplants between ABO blood group-incompatible donors and recipients, using pre-transplant plasmapheresis to deplete anti-A/B antibodies. This led him to explore kidney xenotransplantation, reporting prolongation of function of pig kidneys in baboons in 1989. Finally, in the early 1990s, he investigated the concept of thymic tissue transplantation as a means of inducing tolerance to donor-specific allografts. I hope this summary of his work makes his pioneering contributions better known to the transplant community.