Some infants with acute immune thrombocytopenic purpura (ITP) do not respond to first-line therapy, and currently there is no consensus on therapy for these refractory cases. We describe a 12-week-old infant with acute ITP who was unresponsive to intravenous immunoglobulin and corticosteroid, and developed gastrointestinal bleeding. Several combination therapies were unsuccessful. After four doses of rituximab followed by intravenous immunoglobulin and corticosteroid, his platelet counts gradually increased. Combined therapy which includes rituximab may be a promising treatment for severe acute refractory ITP.