Objective: The aim of this study was to assess prospectively the accuracy of measurement of liver fibrosis with real-time tissue elastography (RTE) in patients with chronic viral hepatitis. Methods: Two hundred and forty-five patients were prospectively enrolled. Nine image features were measured from strain images, and Liver Fibrosis Index (LFI) was calculated from these features. Fibrosis stage was diagnosed from pathological specimens obtained by ultrasound-guided biopsy. LFI and serological markers were compared with pathological diagnosis, and the diagnostic performance of RTE was compared. Results: LFI in stages F0-F1, F2, F3 and F4 was 1.58, 2.03, 2.40 and 2.86, respectively, demonstrating a stepwise increase with increasing severity of liver fibrosis (p < 0.001). LFI in F2 did not significantly differ from that in F3, whereas for all other combinations of stages, there were significant differences. The area under the receiver operating characteristic curve of the LFI, platelet count, aspartate/alanine aminotransferase ratio, aspartate aminotransferase-to-platelet ratio, and FibroIndex for predicting F3 stage or higher (F0-F2 vs. F3-F4) was 0.865, 0.824, 0.708, 0.789 and 0.828, respectively. Conclusions: RTE is useful for diagnosis of liver fibrosis, regardless of stage, in patients with chronic viral hepatitis.