I had … two male chimps … they lived next door to each other in separate cages … before I used one as a [heart] donor. When we put him to sleep in his cage in preparation for the operation, he chattered and cried incessantly … when we removed the body to the operating room, the other chimp wept bitterly and was inconsolable for days. The incident made a deep impression on me. I vowed never again to experiment with such sensitive creatures (8).

—Dr. Christiaan Barnard
The world’s first human-to-human heart transplant surgeon after killing a chimpanzee to use as a heart donor


By the early 1960s, drugs to suppress the rejection of transplanted organs had improved, making transplant surgery a more viable option for patients with serious organ disease. However, availability of human organ donors was (and remains) scarce. With surgical techniques perfected, doctors perceived that all that was needed were more organs, leading some to consider using different species, including chimpanzees, as donors for humans.

Chimpanzee-to-human transplants in America

Three American surgeons used organs from chimpanzees: Drs. Keith Reemstma (kidneys), James Hardy (heart), and Thomas Starzl (liver). (1)

In each case, the surgeries were conducted largely in secret to sidestep the moral issues that abounded. Most of the chimpanzee transplants were eventually announced to the public and were received with much controversy.

Keith Reemstma, MD, a professor at Tulane University from 1963 to 1964, (2) purchased a young chimpanzee named Adam, intending to house him at the hospital laboratory as a potential source of kidneys. Adam was purchased from a circus where he was deemed too difficult and uncooperative to continue performing.

Although many on the hospital’s surgical staff were disturbed by the idea of using chimpanzee organs, Reemstma prevailed and was subsequently presented with an opportunity when a 43-year-old man arrived at the emergency room in danger of imminent death from kidney failure. Adam was killed and his kidneys were transplanted. The ill man survived for only nine weeks.

Five subsequent attempts followed in which Reemstma transplanted chimpanzee kidneys into humans. All but one patient died within a few weeks of the operation—that one patient survived only nine months before he died. (3)

In 1964, James Hardy, MD, attempted to transplant the heart of a chimpanzee into a human—the first and only time this experiment was attempted on American soil. The news of the experiment was poorly received even by the medical community.

“Might makes right”

Hardy, a cardiac surgeon at the University of Mississippi Medical Center in Jackson, had performed experimental surgeries on heart and lung transplants between dogs before he purchased two chimpanzees as potential heart donors.

When attempts to revive a terminal cardiac patient were unsuccessful, one of the chimpanzees was killed to provide a heart for the patient. But the chimpanzee’s heart proved too small to support the human circulation system. The patient died within two hours.

Invited to speak at a surgeon’s conference in New York City several days later, James Hardy was shocked when the moderator introduced him to the large audience by saying: “In Mississippi they keep the chimpanzees in one cage and the Negroes in another cage, don’t they, Dr. Hardy?” (4)

Although the moderator later claimed to be joking, his comments drove home the “Might Makes Right” attitude that was inherent in both American racial oppression and the killing of a nonhuman primate for benefit of the “superior” human primate. Hardy’s lecture was received in total silence and ended without applause. He never performed another chimpanzee transplant.

Continued chimpanzee transplant failures

After the Hardy controversy, only one other American surgeon attempted to transplant organs from chimpanzees to humans. Thomas Starzl, MD, performed three chimpanzee-to-human liver transplants in 1966, 1969 and 1973, all on children who died within days. (5) Starzl abandoned future attempts.

No other chimpanzee-to-human organ transplants by U.S. surgeons have been attempted since.

Outside the U.S. — more transplant failures

Internationally, two surgeons pursued using chimpanzees in human transplant experiments for a brief time in the 1960s. Raffaello Cortesini, an Italian surgeon, performed a number of kidney transplants using chimpanzees. One patient survived for a month. Cortesini expressed interest in breeding chimpanzees for organs, but his idea was received with moral condemnation by the Italians. (6)

In South Africa, Christiaan Barnard, MD, became world famous after performing the first successful human heart transplant in 1967. A decade later he attempted to use chimpanzee hearts to support unstable human patients as they recovered following open-heart surgery. (7) He soon abandoned this method. In his memoir written in 1989, Dr. Barnard wrote of his discomfort with using chimpanzees and vowed never to do so again. (8)

Barnard’s reaction to using chimpanzees as organ donors is mirrored in the reaction of most people. In his history of this subject, Knife to the Heart: The Story of Transplant Surgery, author Tony Stark concludes:

Our closest relative in the animal kingdom might have been the surgeon’s logical first choice, but chimps were too close to humans for the comfort of the rest of society. Ethics, not genetics, won the argument. (9)


(1) Campaign for Responsible Transplantation et al., v. Donna Shalala, Dep’t of Health and Human Services, Petition For Rulemaking To Prohibit The Use Of Xenotransplantation at

(2) Tulane University Health Sciences Center, Rudolph Matas Medical Library, Tulane University Contributions to Medical Science and Education

(3) Stark, Tony. Knife to the Heart: The Story of Transplant Surgery. Macmillan 1996. Chapter 7: pp 156-7.

(4) Ibid. page 162.

(5) Ibid. page 231.

(6) Ibid. page 231.

(7) PBS Frontline, Organ Farm, March 27, 2001, “A History of Xenotransplantation Experiments” at

(8) Barnard, Christiaan, Good Life Good Death, as quoted in Wynne-Tyson, Jon, The Extended Circle: A Commonplace Book of Animal Rights, 1989, Paragon House, New York. Page 9.

(9) Stark, Tony. Knife to the Heart: The Story of Transplant Surgery. Macmillan 1996. Page 162.

xenotransplantation: surgically removing an organ or tissue from one species and transplanting it into a member of a different species.  For more definitions, see Glossary.

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