We report two cases of reticular dysgenesis (RD) successfully treated by BMT utilizing T cell-depleted haploidentical marrow grafts. One child failed to engraft after conditioning with ATG, and the other failed two transplant attempts with cyclophosphamide + ATG, and busulfan + cyclophosphamide + ATG, respectively. Donor engraftment was achieved in both patients following treatment with 700 cGy TBI, with or without other agents. These results, taken together with previous reports in the literature, suggest that children with RD may require more intensive conditioning than patients with other types of severe combined immunodeficiency syndrome.