Epstein-Barr virus-associated smooth muscle proliferations have been reported in immunosuppressed patients with acquired immunodeficiency syndrome and after organ transplantation. We report here a case of a histologically benign case arising in a 48-year-old male who had received immunosuppressive therapy 4 years earlier, after cardiac transplantation. In the necropsy performed for unrelated reasons, an incidental left intramyocardial tumor was discovered. The presence of Epstein-Barr virus was confirmed by EBER-1 in situ hybridization and polymerase chain reaction. To the best of our knowledge, this is the first case of an Epstein-Barr virus-associated smooth muscle proliferation arising in the heart after cardiac transplantation and should be added to the potential complications of this kind of procedure.