Some cases of hepatitis were non A, non B, non C, non D. Hepatitis E virus (Calicivirus) transmission is fecal-oral similar to that of the hepatitis A virus. Viral hepatitis E is endemic and frequently epidemic in many developing countries, but exceptionally observed in France. A high mortality rate was observed in pregnant women. Recently, ELISA assays for IgM anti-HCV are available. Many hepatitis cases (acute and chronic) are not caused by known viruses (non A-non E). Four Flavivirus like have recently been cloned from infectious tamarin serum, derived from human viral hepatitis. Three viruses GB Virus A (GBV-A), GB Virus B (GBV-B) and GB Virus C (GBV-C) were identified. The GB viruses and HG Virus are not genotypes of hepatitis C Virus (HCV) and perhaps that GBV-A/GBV-C and HGV are closely related. GBV-A could be an indigenous tamarin virus. The new hepatitis (non A-non E) viruses were associated with blood transmission and with chronic diseases. The development of specific diagnostic reagents using polymerase chain reaction (PCR) and ELISA assays are essential to answer many questions on the epidemiology (and the incidence of post-transfusion hepatitis), and the pathogenesis of GBV and HGV viruses.