Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive, primary immunodeficiency, characterized by eczema, microthrombocytopenia, recurrent infection, and increased susceptibility to autoimmune diseases and lymphoreticular malignancies. To date, HSCT is the only curative therapy. HSCT using HLA-matched related or unrelated donors is highly successful in treating WAS, but these donors may not always be available. We describe a 20 months-old-boy with WAS, who was transplanted by using highly-purified, 16.11x106/kg CD34 + stem cells from his HLA 2-loci mismatched mother, because of lacking donor and suffering life threatening, ongoing sinopulmonary infections. Conditioning consisted of busulfan (16 mg/kg), cyclophosphamide (200 mg/kg), rabbit anti-thymocyte globulin (10 mg/kg) and fludarabine (160 mg/m 2 ). He received methylprednisolone for graft-versus-host disease (GvHD) prophylaxis. The time for neutrophil, platelet and erythrocyte recovery was 11 days, 14 days and 19 days, respectively. He showed immunologic reconstitution by day +180. He developed grade II aGVHD on day +12, and grade I cGVHD on day +240, resolution achieved in aGVHD with i.v. methylprednisolone and cyclosporine, in cGVHD with oral prednisolone. He is well and alive up to now six years after transplantation. He didn't have any serious infection. Fluorescence in situ hybridization analysis revealed sustained full donor-type engraftment and flow cytometric analysis revealed sustained immunologic reconstitution. The convenient results in this patient can encourage further investigation of the role of using 'high doses' of related haploidentical CD34-selected peripheral blood stem cells in patients with WAS at early stages of disease, before the beginning of severe, life-threatening complications.