Radionuclide ventriculography has proven useful in the ongoing clinical evaluation of cardiac function in orthotopic heart transplant recipients. Two examples of equilibrium radionuclide ventriculograms, one in a 49-year- old woman and the other in a 59-year-old man, both of whom underwent cardiac transplantation, are presented. A 'double right atrium' is noted in both cases on the anterior views. This characteristic appearance is the result of the additive imaging of the residual recipient right atrium anastomosed to the right atrium of the donor heart as part of the surgical procedure. Recognition of this normal postsurgical appearance will help avoid confusion with atrial anastomotic pathology.