Wiskott-Aldrich syndrome, an X-linked primary immunodeficiency can be cured by bone marrow transplantation. Umbilical cord haemopoietic stem cells are increasingly used as an alternative to bone marrow; advantages include ready availability, no risk to the donor, low rate of viral contamination, and low risk of graft versus host disease. Disadvantages include low stem cell dose for larger patients and lack of stem cells for boost infusions following the initial procedure. We report the case of a child with Wiskott-Aldrich syndrome who underwent cord blood stem cell transplantation with two separate cord blood units, 8 days apart.