We report here the first case with Diamond-Blackfan anemia (DBA) who responded to rituximab. The patient is an 8-yr-old Japanese girl with refractory DBA accompanied by complex congenital heart disease. She received two doses of rituximab, 375 mg/m(2)/wk. She became transfusion independent 6 months after the treatment without any serious side effect. However, after 8 months of transfusion-free period, her condition returned to the pretreatment level with recovery of peripheral B cells. Rituximab may be a successful therapy for refractory DBA where B cells play a crucial role in the pathogenesis of the severe anemia.