Post-transplant lymphoproliferative disorders (PTLD) are a well known complication after orthotopic heart transplantation (OHT). Although Epstein-Barr virus (EBV) infection has long been implicated in the pathogenesis of such disorders, other factors may play a part. Because of its lymphotropic properties, hepatitis C virus (HCV) may induce clonal expansion of B-lymphocytes and lead to PTLD. The aim of this study was to evaluate the potential association between HCV and EBV infection and PTLD in OHT patients. The retrospective study considered 404 adult patients screened for HCV. EBV serology, histology, and molecular analysis on tissue biopsies were performed in the PTLD patients (10/404, 2.5%). HCV positivity was found in 36/404 (8.9%) patients. The EBV genome was expressed on all neoplastic tissue samples analyzed. A higher proportion of HCV-positive patients developed PTLD than the HCV-negative cases (8% vs 2%, P = 0.017). EBV has a demonstrated role in the onset of PTLD, but HCV infection probably has to be considered as well.