Publisher Summary This chapter reviews the advances made in human leukocyte antigens and transplantation. The transplantation of skin from one part of the body to another are performed since ancient times, not only in the repair of injuries caused by warfare but also to make good mutilations imposed as punishments for infidelity, thievery, and other misdemeanors. With regard to solid organ transplantation, the first half of this century saw a few isolated and ill-fated attempts made for transplanting kidneys removed from cadavers, but the practice did not attract significant interest until the early 1950s. Several examples of transplantation including liver, heart, renal, and bone marrow transplantation are provided in the chapter in which prospective human leukocyte antigen (HLA) matching is impractical because of the urgency of the procedure. Unlike in some experimental animals, no immunological privilege has been found associated with liver transplantation in humans. Acute rejection is therefore a major problem. The chapter also discusses the role of HLA molecules in immune responses and the usage of immunosuppression for reducing graft rejection. The chapter concludes with a discussion of pancreas transplantation, which is currently performed to improve life rather than save it.