In pediatric acute immune thrombocytopenic purpura (ITP) cases, it is usually possible to determine an underlying pathology; among them, viral infections are the leading causative agents. In this report, we describe two cases of acute ITP complicated secondary to parvovirus B19 or Epstein-Barr virus (EBV) infections who were unresponsive to initial therapeutic measures, but who responded to long-term intravenous immunoglobulin (IVIG) treatment, given weekly for five to eight weeks.