Persistent infection with human parvovirus B19 (B19) is primarily associated with chronic bone marrow failure in immunocompromised patients, but occasionally this organism may also affect immunocompetent hosts. B19 is also suggested as a causative agent of organ failure during bone marrow transplantation (BMT). We herein report the case of a 9-year-old girl with no previous history of immunodeficiency who developed severe aplastic anemia concurrent with B19 persistent infection. Both immunoglobulin (Ig)M antibody to B19 and B19 DNA identified by real-time polymerase chain reaction were found in the patient’s serum at time of diagnosis of aplastic anemia. No giant proerythroblasts were found in her bone marrow at diagnosis. Although intravenous administration of Ig (IVIg) reduced serum B19 DNA, the aplastic status of her bone marrow did not improve. Both aplastic anemia and persistent B19 viremia were successfully treated by BMT from an HLA-identical sibling donor. Serum B19 DNA increased temporarily after BMT; however, neither organ nor marrow failure was observed. B19 DNA disappeared from the serum 2 months after BMT, suggesting that a normal immune response was restored by BMT and terminated the B19 viremia. During BMT, use of high-titer IVIg for B19 might prevent B19-associated organ failure.