Organ transplantation may be a procedure during which an organ is far away from one body and placed within the body of a recipient, to exchange a damaged or missing organ. The donor and recipient could also be at an equivalent location, or organs could also be transported from a donor site to a different location. Organs and/or tissues that are transplanted within an equivalent person's body are called auto grafts. Transplants that are recently performed between two subjects of an equivalent species are called allografts. Allografts can either be from a living or cadaveric source.

Organs that are successfully transplanted include the guts, kidneys, liver, lungs, pancreas, intestine, thymus and uterus. Tissues include bones, tendons (both mentioned as musculoskeletal grafts), corneae, skin, heart valves, nerves and veins. Worldwide, the kidneys are the foremost commonly transplanted organs, followed by the liver then the guts. Corneae and musculoskeletal grafts are the foremost commonly transplanted tissues; these outnumber organ transplants by quite tenfold.

Organ donors could also be living, dead, or dead via circulatory death. Tissue could also be recovered from donors who die of circulatory death, also as of cerebral death – up to 24 hours past the cessation of heartbeat. Unlike organs, most tissues (with the exception of corneas) are often preserved and stored for up to 5 years, meaning they will be "banked". Transplantation raises variety of bioethical issues, including the definition of death, when and the way consent should tend for an organ to be transplanted, and payment for organs for transplantation. Other ethical issues include transplantation tourism (medical tourism) and more broadly the socio-economic context during which organ procurement or transplantation may occur. a specific problem is organ trafficking. There’s also the moral issue of not holding out false hope to patients.