Richard J. O'Reilly, MD -- Chair, Department of Pediatrics; Chief, Pediatric Bone Marrow Transplant Service; Claire L. Tow Chair in Pediatric Oncology Research

Richard J. O'Reilly, MD

Pediatric Oncology


Claire L. Tow Chair in Pediatric Oncology Research

Clinical Expertise

Pediatric Oncology; Allogeneic and Autologous Bone Marrow and Peripheral Blood Stem Cell Transplantation; Congenital and Acquired Diseases of Hematopoiesis and Immunity

New Patient Appointments

Scheduling a visit is easy. Click below or call us to get started.

Accepted Insurance Providers

Dr. O'Reilly accepts the following list of insurance providers. Select your insurance provider to see more details.

Contact and Location

Locations map

Find a Convenient Location

Memorial Sloan Kettering has locations throughout New York City, Long Island, New Jersey, and Westchester. These locations offers many services, including screening, chemotherapy, and medical testing.

About Me


MD, University of Rochester School of Medicine


Pediatrics - Children's Hospital Medical Center


Infectious Disease - Children's Hospital Medical Center/Beth Israel Hospital

Board Certifications


As former Chair of the Department of Pediatrics, I oversaw all aspects of the clinical, medical education, and research endeavors the department is privileged to provide. My clinical expertise is in bone marrow transplantation and the treatment of children with congenital and acquired immunological deficiencies. I have particular expertise in treating genetic diseases that impair hematopoiesis — the formation of blood cells — as well as pediatric leukemias. I am also an authority on transplantation immunology and cellular therapies.

I’ve always been fascinated by the immunology of transplantation and our ability to use this approach to cure diseases. I was involved in the first transplant of bone marrow from an unrelated donor to a patient in 1973. This opened the possibility of a transplant to the majority of patients who lack a matched brother or sister. Since then, we have greatly refined this approach. In fact most of the transplants we perform are now from unrelated donors.

I also conduct laboratory and clinical research, and have led national studies of new therapies for children with genetic immunodeficiencies and both adults and children with leukemia and other life-threatening blood diseases. I and my colleagues developed and introduced methods for removing T cells from the donor’s transplant. (T cells are the white blood cells that can attack the tissues of the patient and cause a complication called graft-versus-host disease [GvHD]). This approach has proven to be an effective way to prevent GvHD, and has allowed us to transplant marrow from genetically half-matched donors, such as a mother or father, without causing severe or fatal GvHD. We’ve also developed and introduced in clinical trial, new immune cell therapies to manage other potential complications of transplantation, such as Epstein-Barr-virus lymphomas and cytomegalovirus infections. Today there is no more “boy in the bubble,” thanks to the advances we’ve made in bone marrow transplantation.

My fellow scientists and I are now developing cellular therapies that could be used to enhance the resistance of bone marrow transplant recipients to not only serious infections but also their underlying cancers. We’re aiming to create novel systems to elicit an immune response in the patient against infectious organisms or residual cancer cells.

I am privileged to work with a dedicated and experienced team of professionals who have the capacity to assess clinical challenges and develop innovative solutions. We share a passion for delivering good medicine. We’ve also developed support systems for patients and their families that are second to none.

I have shared my experience and knowledge with fellows and residents, many of whom have gone on to establish bone marrow transplant programs at institutions around the world. I am past-President and currently a member of the Board of the Damon Runyon-Walter Winchell Cancer Fund, and on the Board of the Children’s Oncology Society of New York, which runs the local Ronald McDonald House. I have won several awards for my work, including honors from the American Society of Clinical Oncology, the Society of Translational Oncology, the American Society for Blood and Marrow Transplantation, and Leiden University in The Netherlands.

Awards and Honors

  • New York Magazine Top Doctors (2002-2016)


Doctors at Memorial Sloan Kettering work as teams, with specialists from all different areas. This allows us to consider all your needs together, and to give you the best possible care.

Clinical Trials

Smiling doctors in the lab

Find a Clinical Trial for You

Memorial Sloan Kettering's doctors and scientists are constantly developing new treatments for cancer. MSK is typically running hundreds of clinical trials at a given time.

You may be able to participate in a clinical trial even if you are new to MSK. Search our online directory to find trial information and see more about who can participate.

Research and Publications

View Dr. O'Reilly's Lab

Dinsmore R, Kirkpatrick D, Flomenberg N, et al. Allogeneic bone marrow transplantation for patients with acute lymphoblastic leukemia. Blood 1983; 62 :381

Shank B, Chu FC, Dinsmore R, et al. Hyperfractionated total body irradiation for bone marrow transplantation. Results in seventy leukemia patients with allogeneic transplants. Int J Radiat Oncol Biol Phys 1983; 9 :1607

Brochstein JA, Kernan NA, Groshen S, et al. Allogeneic bone marrow transplantation after hyperfractionated total-body irradiation and cyclophosphamide in children with acute leukemia. N Engl J Med 1987; 317 :1618

Papadopoulos EB, Carabasi MH, Castro-Malaspina H, et al. T-cell-depleted allogeneic bone marrow transplantation as postremission therapy for acute myelogenous leukemia: freedom from relapse in the absence of graft-versus-host disease. Blood 1998 Feb 1;91(3):1083-90 1998; 91 :1083

Boulad F, Steinherz P, Reyes B, et al. Allogeneic bone marrow transplantation versus chemotherapy for the treatment of childhood acute lymphoblastic leukemia in second remission: a single-institution study. J Clin Oncol 1999; 17 :197

Walters MC, Sullivan KM, O’Reilly RJ, et al. Bone marrow transplantation for thalassemia. The USA experience.. Am J Pediatr Hematol Oncol 1994; 16 :11

Boulad F, Giardina P, Gillio A, et al. Bone marrow transplantation for homozygous beta-thalassemia. The Memorial Sloan Kettering Cancer Center experience. Ann N Y Acad Sci 1998; 850 :498

Gillio AP, Boulad F, Small TN, et al. Comparison of long-term outcome of children with severe aplastic anemia treated with immunosuppression versus bone marrow transplantation. Biol Blood Marrow Transplant 1997; 3 :18

O’Reilly RJ, Dupont B, Pahwa S, et al. Reconstitution in severe combined immunodeficiency by transplantation of marrow from an unrelated donor. N Engl J Med 1977; 297 :1311

O’Reilly RJ, Kapoor N, Pollack M, et al. Reconstitution of immunologic function in a patient with severe combined immunodeficiency following transplantation of marrow from an HLA-A,B,C nonidentical but MLC-compatible paternal donor. Transplant Proc 1979; 11 :1934

Reisner Y, Kapoor N, Kirkpatrick D, et al. Transplantation for severe combined immunodeficiency with HLA-A,B,D,DR incompatible parental marrow cells fractionated by soybean agglutinin and sheep red blood cells. Blood 1983; 61 :341

O’Reilly RJ, Keever CA, Small TN, et al. The use of HLA-non-identical T-cell-depleted marrow transplants for correction of severe combined immunodeficiency disease. Immunodefic Rev 1989; 1 :273

Brochstein JA, Gillio AP, Ruggiero M, et al. Marrow transplantation from human leukocyte antigen-identical or haploidentical donors for correction of Wiskott-Aldrich syndrome. J Pediatr 1991; 119 :907

Castro-Malaspina H, Childs B, Laver J, et al. Hyperfractionated total lymphoid irradiation and cyclophosphamide for preparation of previously transfused patients undergoing HLA-identical marrow transplantation for severe aplastic anemia. Int J Radiat Oncol Biol Phys 1994; 29 :847


Publications on PubMed

Visit PubMed for a full listing of Dr. O'Reilly’s journal articles. Pubmed is an online index of research papers and other articles from the US National Library of Medicine and the National Institutes of Health.