Browse Health
License & Identifications

A medical license is required for a doctor to practice medicine in a particular state. Requirements vary by state but most require, at a minimum, post-graduate training in the doctor’s specific specialty. An NPI number is a national identifier unique to an individual health care provider and is managed by the Center for Medicare & Medicaid Services (CMS).

Patient Reviews

Patient comments (15)

The overall average patient rating of Dr. Leonard Klein, Internist is Excellent. Dr. Klein has been reviewed by 16 patients who have provided 15 comments. The rating is 5 out of 5 stars.

Patient Ratings
Ease of Appointment 5.0
Promptness 5.0
Courteous Staff 5.0
Accurate Diagnosis 5.0
Bedside Manner 5.0
Spends Time with Me 5.0
Follows Up After Visit 5.0

Specialties & Research

Dr. Leonard Klein, MD is board certified in Hematology.

  • He has special expertise in 17 areas:
  • Acute Myeloid Leukemia
  • Adult T-Cell Leukemia-Lymphoma
  • Blood Disorders
  • Blood Transfusion
  • Bone Marrow Transplantation
  • Breast Cancer
  • Chronic B-Cell Lymphocytic Leukemia
  • Chronic Myeloid Leukemia
  • Chronic Myelomonocytic Leukemia
  • Clinical Research
  • Deep Vein Thrombosis
  • Epidemiology
  • Hepatitis C
  • Leukemia
  • Lymphoma
  • Metastatic Breast Cancer
  • Multiple Myeloma (Cancer of Plasma Cells)

Education & Awards

Dr. Klein graduated from State University of New York at Buffalo. He has 2 awards.

Castle Connolly's Top Doctors™ (2012 - 2013)
Patients' Choice Award (2012)


Dr. Klein has 5 hospital affiliations:

  • Northwest Community Hospital 
  • Advocate Lutheran General Hospital 


  • Spanish

> > > > Dr. Leonard Klein, MD

Similar doctors nearby

Dr. John Eklund

Internal Medicine
13 years experience
Niles, IL

Dr. David Hakimian

24 years experience
Niles, IL

Dr. Leonard Kosova

Internal Medicine
50 years experience
Niles, IL

Dr. Bruce Kaden

39 years experience
Niles, IL

Dr. Susan Brown

27 years experience
Niles, IL

Dr. William Miller

Anatomic Pathology & Clinical Pathology
33 years experience
Park Ridge, IL
Search All Similar Doctors
Additional Information
Dr. Leonard M Klein MD is a male Hematologist, has 36 years of experience and practices in Hematology.
Where does Dr. Leonard M. Klein practice?
Dr. Leonard Klein has 4 office locations.
Dr. Leonard Klein practices Hematology near Niles, IL.
Additional practice locations include: Chicago, IL and Arlington Heights, IL.
See Niles Hematologists.