Hepatitis G virus (HGV) may cause acute and chronic infection in humans but its role in parenchymal liver injury and chronic hepatitis is obscure. In this study, the importance of HGV was investigated in patients with elevated aminotransferases alanine transaminase/aspartate transaminase (ALT/AST) levels of unknown etiology. We included 56 patients with elevated ALT/ AST levels of unknown etiology and 81 healthy controls in the study. HGV RNA was investigated by the reverse transcription polymerase chain reaction. The other possible causes of transaminase elevation were excluded with detailed biochemical and serologic tests. Liver biopsy was performed on 47 patients for histologic examination. HGV RNA was detected in only two patients (3.3%) and in one control (1.2%). There was no statistical difference between the groups. Liver biopsy revealed minimal inflammatory changes and steatosis in HGV RNA-positive patients. These observations indicated that HGV prevalence is not different from that of the general population in patients with liver transaminases elevation of unknown etiology. The role of this novel virus in the pathogenesis of chronic liver injury of unknown etiology appears insignificant in our geographic area.