Domino heart transplantation has been well described in adults, but has not previously been reported in infant patients. We report the successful transplantation of a 'domino' heart from a 3-month-old infant with primary pulmonary hypertension undergoing heart-lung transplantation, into a 3-month-old infant with complex congenital heart disease. Both infants have survived past 1 year post-transplant, and neither infant has experienced any clinically significant allograft-related complications. Echocardiography and cardiac catheterization of the domino heart have consistently demonstrated stable hypertrophy of the right ventricle (RV) and interventricular septum, but good right and left ventricular function. Domino heart transplant surgery may be an effective way to provide 'pre-conditioned' donor hearts to infants urgently in need of heart transplantation.