The surgical technique of heterotopic heart transplantation is detailed and illustrated. The donor heart is excised after cardioplegic arrest and topical cooling; its preparation and implantation in the recipient are described. Emphasis is placed on ensuring nonrestrictive anastomoses between the left and right atria of the recipient and the donor, on estimating the optimal length of the donor aorta, and on the insertion of a prosthetic graft between the donor and the recipient pulmonary arteries. Forty-six such transplants have been performed to date without operative or early postoperative mortality related to technical problems. © 1983, The Society of Thoracic Surgeons. All rights reserved.