An 11-year-old boy with severe chronic active Epstein-Barr virus infection (CAEBV) underwent successful cord blood transplantation (CBT) after consecutive failure of peripheral blood and bone marrow transplantation from his HILA-mismatched mother. CB cells from an unrelated donor were infused after conditioning with total body irradiation (12 Gy), melphalan (120 mg/m(2)), and etoposide (600 mg/m(2)). Complete remission without circulating EBV-DNA has continued for 15 months after a delayed hematologic recovery. This is the first successful report of CBT for CAEBV. CB may therefore be an alternate source of stem cells for the curative treatment of CAEBV, despite the absence of EBV-specific cytotoxic T lymphocytes.