In order to prevent penaeid acute viremia (PAV) in seed production of kuruma prawn Penaeus japonicus, the presence of penaeid rod-shaped DNA virus (PRDV) in the ovary and receptaculum seminis was examined by polymerase chain reaction (PCR). The detection rate of PRDV was always higher in the receptaculum seminis than in the ovary. The prevalence of the virus in the receptaculum seminis became higher after spawning, especially in the spawners that required a longer period to induce spawning. PAV occurred in postlarvae cultured at Kamiura Station of Japan Sea-Farming Association in 1997 when segregation of spawners was made based on the results of PRDV detection from ovaries before spawning, whereas the disease did not occur in 1998 or 1999 when segregation of eggs was performed according to the result of virus detection from the receptaculum seminis after spawning. These results indicate that the selection of eggs should be done in the hatchery based on the results of PCR detection from receptaculum seminis of spawners after spawning.