We retrospectively analyzed the transplantation outcomes of 31 patients with primary immunodeficiency diseases treated at our center (All Children's Hospital, University of South Florida) since its inception in 1986. The primary immune diseases included severe combined immunodeficiency, Wiscott-Aldrich syndrome, X-linked hyper-IgM syndrome, and chronic granulomatous disease. The age of the patient's at the time of transplant ranged from 1 month to 19 years, and conditioning regimens varied based on the patients underlying disease. In 23 patients, the graft source was bone marrow, 4 patients received umbilical cord blood grafts and 4 patients received peripheral blood stem cell grafts. Better survival rates were observed in those patients transplanted at a younger age and free of infections, demonstrating that transplantation at an early age before significant infections, autoimmune manifestation and malignant transformation have occurred is beneficial.