A previously healthy 11-year-old white female presented with a Coomb's positive hemolytic anemia and reticulocytopenia. The patient was treated with prednisone (6.4 mg/kg/day) and had a stable hemoglobin with subsequent recovery of reticulocytes by 7 days. Bone marrow aspiration showed hypercellularity with arrest of red cell maturation. The patient's serum contained specific IgM and IgG antibodies to parvovirus B19. Our report confirms parvovirus B19 as a cause of reticulocytopenia at presentation in autoimmune hemolytic anemia. Immunosuppressive therapy with prednisone did not appear to significantly prolong the course of the B19 infection.