Background and Objectives: A collaborative study was organised to establish a hepatitis A virus (HAV) RNA standard for genomic amplification assays (GAT). Materials and Methods: A panel of 10 samples consisting of a 10–fold serial dilution of wild–type HAV diluted in HAV–negative cryosupernatant and samples of the diluent were sent to 14 laboratories in duplicate for testing for HAV RNA by the polymerase chain reaction. Results: Data returned by 12 laboratories indicated that the sensitivities of the assays performed by different laboratories were fairly close: there was a 100–fold difference in sensitivity between the majority of laboratories. Only one laboratory reported false–positive results. Conclusion: A 10–5 dilution of the virus in cryosupernatant could be an appropriate working reagent for GAT assays for HAV RNA in plasma pools.