This report exemplified a success of unrelated donor cord blood transplantation (CBT) in a 4-month-old boy with chronic granulomatous disease (CGD). Following Bu14/Cy200/ATG conditioning, the patient received an HLA 2-locus-mismatched cord blood unit, and the total number of infused nucleated cells was 11.52 x 10(7)/kg. Neutrophil engraftment was achieved on day +13, and a platelet count greater than 20 x 10(9)/L was achieved on day +50. The neutrophil oxidative burst was 100% normal with full donor lymphocyte reconstitution at 8 months post-transplant. This case highlights that unrelated donor CBT for CGD is potentially safe and feasible, even in early infancy, when an appropriately matched related or unrelated donor is unavailable.