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Department Translational Hematology and Oncology Research
Primary Location Cleveland Clinic Main Campus
Type of Doctor Adults Only
Languages English, German, Polish, Russian
Surgeon No
Cleveland Clinic Main Campus
Primary Location

Cleveland Clinic Main Campus

Specialties & Treatments

Treatment & Services

  • Benign Hematology
  • Bone Marrow Transplantation
  • Cancer Center
  • Chemotherapy
  • Clinical Trials
  • General Hematology
  • Molecular Diagnostics
  • Molecular Therapy
View all 8 Treatment & Services +

Specialty in Diseases & Conditions

  • Acute Lymphocytic Leukemia (ALL)
  • Acute Myeloid Leukemia
  • Anemia
  • Aplastic Anemia
  • Autoimmune Neutropenia
  • Blood Clots
  • Blood Disorders
  • Bone Marrow Failure Disorders
  • Cancer
  • Chronic Anemia
  • Chronic Neutropenia
  • Congenital Amegakaryocytic Thrombocytopenia (CAMT)
  • Congenital Dyserythropoietic Anemia
  • Congenital Neutropenia
  • Cytopenia
  • Diamond Blackfan Anemia (DBA)
  • Dyskeratosis Congenita
  • Fanconi Anemia
  • Hematologic Malignancies
  • Large Granular Lymphocytic Leukemia
  • Leukemia
  • Leukopenia
  • LGL
  • Myelodysplasia
  • Myelodysplastic Syndrome (MDS)
  • Paroxysmal Nocturnal Hemoglobinuria
  • PNH
  • Pure Red Cell Aplasia
  • Rare Cancer and Blood Disease Program
  • Shwachman-Diamond Syndrome (SDS)
  • T-Cell Large Granular Lymphocyte Leukemia (LGL)
  • Thrombocytopenia Absent Radii Syndrome (TAR)
View all 32 Specialties +


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About Jaroslaw Maciejewski, MD, PhD

Jaroslaw P. Maciejewski, MD, PhD, FACP, is Staff Physician in the Cleveland Clinic Department of Hematologic Oncology and Blood Disorders and is board certified in hematology and internal medicine. He is also Chairman of the Department of Translational Hematology and Oncology Research at the Taussig Cancer Institute and has an academic rank of Professor of Medicine at the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University. In Case Comprehensive Cancer Center Dr. Maciejewski is associate director for Translational Research and member of Executive Committee. 

Recognized for his scholarly achievements as a physician scientist active in the field of hematology, Dr. Maciejewski is an elected member of the American Society for Clinical Investigation (ASCI), American Association of Physicians (AAP) and a Fellow of American College of Physicians (ACP). He is also a member of the Medical Advisory Board of the International Aplastic Anemia and Myelodysplastic Syndrome International Foundation (AA&MDS IF), editorial board of Leukemia Journal and has also been a reviewer of various NIH DOD and LLS study sections both as permanent member or (ad hoc) reviewer. Dr. Maciejewski also chaired the American Society of Hematology Scientific Committee for Myeloid Neoplasia, and AA&MDS IF Medical Advisory Board for one and two terms, respectively. As a practicing hematologist his clinical areas of expertise include bone marrow failure syndromes (including aplastic anemia, myelodysplastic syndrome, large granular lymphocyte leukemia, paroxysmal nocturnal hemoglobinuria in pure red cell aplasia), and myeloid leukemias.

As a translational physician-scientist, Dr. Maciejewski is a world renowned expert in leukemia genetics and bone marrow failure. Dr. Maciejewski’s research deals with the molecular pathogenesis of these disorders with the focus on various specific aspects of stem cell biology, genetics, cytogenetics and immunobiology as well as targeted drug development. His research has been supported by AA&MDS IF, Leukemia Lymphoma Society, Taub foundation, Evans MDS Foundation, Department of Defense, and NIH RO1s, U55, R21s and K24. Dr. Maciejewski is currently funded through the prestigious Distinguished NIH Investigator (R35) Award. His scientific profile lists 42,000 citations, H-index of 105 and i10 index of 404.

Dr. Maciejewski attended medical school at the Medical School Charite, Humboldt University, Berlin, Germany receiving his medical degree and doctorate from the Institute for Medical Immunology at Humboldt University Medical School. He completed his internal medicine residency at the University of Nevada, School of Medicine in Reno, NV and Hematology Fellowship at the National Institutes of Health Medical Center, Bethesda, MD. He also completed his postdoctoral research fellowship at the Hematology Branch of the National Heart, Lung and Blood Institute (NHLBI) in Bethesda, MD where he later served as Staff Scientist before joining Cleveland Clinic in 2001 as Staff Physician and Section Head of Experimental Hematology. In 2009, Dr. Maciejewski was appointed Chairman Department of Translational Hematology and Oncology Research at the Taussig Cancer Institute a position he currently holds.

Education & Professional Highlights

Education & Professional Highlights


Education & Fellowships

Fellowship - National Heart, Lung and Blood Institute
Bethesda, MD USA

Residency - University of Nevada School of Medicine
Internal Medicine
Reno, NV USA

Medical Education - Humboldt University Berlin, Medical School (Charite)

Medical Education - Humboldt University Berlin, Medical School (Charite)

Professional Highlights

  • Department Chair, Translational Hematology and Oncology Research
  • Professor of Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University


  • Internal Medicine - Hematology

Specialty Interests

Bone marrow failure syndromes including aplastic anemia, myelodysplastic syndrome, large granular lymphocyte leukemia, paroxysmal nocturnal hemoglobinuria, autoimmune neutropenia, pure red cell aplasia and other refractory anemias, cytopenias, acute lymphocytic leukemia

Awards & Honors

  • America's Best Doctors


  • American Society of Clinical Investigation
  • American Medical Association
  • American Society of Hematology
  • American Association of Physicians
  • Member, Medical Advisory Board, Aplastic Anemia and MDS International Foundation
  • Fellow in FACP since 7/1/09 from the Ohio Chapter 7/1/09
  • American Society of Clinical Investigation
Research & Publications

Research & Publications

See publications for Jaroslaw Maciejewski, MD, PhD.

(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

Industry Relationships

Industry Relationships

Cleveland Clinic physicians and scientists may collaborate with the pharmaceutical or medical device industries to help develop medical breakthroughs or provide medical expertise or education. Cleveland Clinic strives to make scientific advances that will benefit patient care and support outside relationships that promise public benefit. In order for the discoveries of Cleveland Clinic physicians' and scientists' laboratories and investigations to benefit the public, these discoveries must be commercialized in partnership with industry. As experts in their fields, Cleveland Clinic physicians and scientists are often sought after by industry to consult, provide expertise and education.

To assure professional and commercial integrity in such matters, Cleveland Clinic maintains a program that reviews these collaborations and, when appropriate, puts measures in place to minimize bias that may result from ties to industry. Cleveland Clinic publicly discloses the names of companies when (i) its physicians/scientists receive $5,000 or more per year (or, in rare cases, equity or stock options) for speaking and consulting, (ii) its physicians/scientists serve as a fiduciary, (iii) its physicians/scientists receive or have the right to receive royalties or (iv) its physicians/ scientists hold any equity interest for the physician's/scientist's role as inventor, discoverer, developer, founder or consultant.* In publicly disclosing this information, Cleveland Clinic tries to provide information as accurately as possible about its physicians' and scientists' connections with industry.

As of 1/17/2022, Dr. Maciejewski has reported the financial relationships with the companies listed below. In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.

Consulting and/or Speaking. Dr. Maciejewski receives fees of $5,000 or more per year (or, in rare cases, equity or stock options) as a paid consultant, speaker or as a member of an advisory committee for the following companies:

  • Regeneron Pharmaceuticals, Inc.
  • Celgene Corporation (a wholly-owned subsidiary of Bristol-Myers Squibb)
  • Roche (Hoffman-La Roche, Ltd.)

Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.

* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.

Patient Satisfaction Reviews

47 Patient Satisfaction Reviews

The Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our nationally-recognized Press Ganey Patient Satisfaction Survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.

Responses are measured on a scale of 1 to 5 with 5 being the best score.

The comments are submitted by patients and reflect their views and opinions. The comments are not endorsed by and do not necessarily reflect the views of Cleveland Clinic.

Overall Star Ratings
4.9 out of 5
Explains 4.9
Courtesy, Respect & Concern 4.9
Patient Rating of Doctor 4.9

11 Patient Comments

Reviewed on May 10, 2023

Dr. Maciejewski is most excellent in the care and communication he provides

Reviewed on Apr 19, 2023

Dr. Maciejewski and Dr Ullah his fellow, are very attentive, they listen, and explain things well.

Reviewed on Apr 12, 2023

I had a wonderful experience with Dr. M. For the first time in 2 and a half years, I feel very hopeful for my future. His expertise is evident and I am so grateful that I was referred to him.

Reviewed on Apr 12, 2023

Dr. Maciejewski is like family!

Reviewed on Mar 15, 2023

Dr. M is a wonderful doctor. He is very patient with my mom as she has a hard time hearing. He takes his time every appointment no matter what time of day it is. He also answers all our questions and makes us feel at ease with everything going on. I personally thank him every appointment!

Reviewed on Feb 15, 2023

Very professional staff from parking attendants, greeting staff, receptionist, lab staff, nurses, medical staff and of course Dr. M.

Reviewed on Feb 8, 2023

Dr. M and his staff have always been tremendous, and this visit was no exception. They always take the time to answer any questions I have, and I never feel as if I am being rushed out of my appointment.

Reviewed on Dec 21, 2022

Dr M is both brilliant and caring. Who could ask for anything more.

Reviewed on Nov 2, 2022

Dr. Maciejewski and his staff work together like a well oiled machine! They were confident, knowledgeable and made me feel comfortable. Dr. Maciejewski explained that there are several different treatment options for my condition and that he will work to find the one best for me. .For the first time, since I have been diagnosed, I feel that I have hope.

Reviewed on Oct 12, 2022

I am very blessed to have a physician that is an expert in the field of bone marrow disorders.

Reviewed on Jun 22, 2022

Dr. Maciejewski is very difficult to understand and a fast talker but tries to make an effort to use hand gestures and other tools to help with the issue. He seems very knowledgeable and caring.

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