A 21-year-old previously healthy male presented with prolonged fever of 3 weeks duration and profound agranulocytosis that did not respond to treatment with granulocyte-stimulating factors. A bone marrow biopsy demonstrated an absence of myeloid lineage. Acute parvovirus B19 infection was diagnosed by the presence of both IgM and IgG anti-parvovirus antibodies. Two days treatment with intravenous immunoglobulins (IVIg) resulted in complete recovery. The role of treatment with immunoglobulins in acute and persistent parvovirus infection is discussed.