Hepatitis E virus (HEV), the causative agent of enteric non-A, non-B hepatitis, is a positive-stranded RNA virus. Because of the virus's inability to grow in culture, several nonhuman primates have been used for the propagation of HEV. Using strand-specific reverse transcription-polymerase chain reaction (RT-PCR), we demonstrate the presence of negative-stranded HEV RNA replicative intermediates in the livers of infected animals. This constitutes the first direct evidence of HEV replication in the liver of the infected animals and reinforces the validity of such a model to study HEV infection, disease pathogenesis, and immunity.