Occult hepatitis C virus (HCV) infection (OCI) is defined as the presence of the HCV genome in either liver tissue or peripheral blood monocytes, despite constantly undetectable HCV-RNA in serum. The prevalence of OCI has been thought extremely rare in the immunocompetent host.1 In contrast, this statement may not hold true in cases where antiviral immunity is weakened. In fact, our study results revealed an unexpectedly high prevalence of OCI among recurrent HCV-infected patients after undergoing orthotopic liver transplantation (OLT) who achieved a sustained virologic response (SVR) with direct-acting antiviral agents (DAAs).