We investigated the infection of nervous necrosis virus (NNV) in seven band grouper Hyporthodus septemfasciatus broodstocks, which have been reared in aquaculture farms in South Korea during 2012-2014. To investigate the prevalence of NNV within the broodstock, egg, sperm, and blood were sampled in the spawning season. The egg and sperm samples were subjected to a nested reverse transcription (RT) polymerase chain reaction (PCR) assay to detect NNV and were inoculated on SSN-1 cells to culture the virus. Blood samples were used to detect antibodies against NNV using enzyme linked immunosorbent assay (ELSIA). Positive values from ELISA were found in 39 of 162 samples (24%) in 2012, and 13 of 28 samples (46%) in 2014. Additionally, 4 of 34 broodstocks (11%) investigated in 2013-2014 were determined to be carriers from the nested RT-PCR and in vitro cultivation. The broodstocks in which antibodies against NNV were detected by ELISA, or in which NNV was detected by the nested RT-PCR assay, posed a risk of vertical transmission of NNV. Therefore, it is necessary to select virus-free broodstocks in seed production to reduce the possibility of the vertical transmission of NNV.