Direct detection of hepatitis C virus (HCV) by reverse transcription (RT) and polymerase chain reaction (PCR) has clinical impact on diagnosis and the assessment of anti-viral therapy. However, recent results of a quality control study on the detection of HCV-RNA by RT-PCR revealed inappropriate sensitivity and specificity in the majority of participating laboratories. In this study we evaluated the first standardized RT-PCR-assay (Amplicor HCV) for routine detection of hepatitis C virus in serum samples from patients with hepatitis C (n = 111), patients with resolved acute hepatitis C (n = 7) and controls (n = 101). The Amplicor HCV assay was convenient to handle, detected all genotypes of the hepatitis C virus commonly present in Europe (type 1, 2 and 3 according to Simmonds et al.) and had a lower detection limit of 10(2)-10(3) copies as assessed by quantifiable HCV-specific RNA templates. In the clinical evaluation the Amplicor HCV system reached a sensitivity of 100% and a specificity of 97%.