The association of cartilage hair hypoplasia (CHH) with severe combined immunodeficiency (SCID) has been known for more than three decades. Bone marrow transplantation (BMT) remains the only effective treatment that might cure SCID. Surprisingly little has been reported on the experience with BMT in CHH. We report here survival and long-term reconstitution of immunity after BMT in three patients with CHH. Regardless of whether a related human leukocyte antigen-matched or unrelated matched donors were used as the source of BMT, all patients are alive and well 5-20 years after BMT. Engraftment appears robust with most cells of donors origin. Repeated evaluation of the immune system showed normal cellular and humoral immunity. Our results should encourage the use of BMT in patients with CHH who have profound immunodeficiency.