Browse Health
30 years of experience
Accepting new patients
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).

Learn more about Dr. Dennis O'Brien:

View the full profile to get information on:

  1. Qualifications
  2. What's important to you

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Patient Reviews

  • Currently 3.5 of 4 stars
Patient comments (3)

The overall average patient rating of Dr. Dennis O'Brien is Excellent. Dr. O'Brien has been reviewed by 17 patients who have provided 3 comments. The rating is 3.5 out of 4 stars.

Patient Ratings
Ease of Appointment 3.2
  • Currently 3.2 of 4 stars
Promptness 3.0
  • Currently 3 of 4 stars
Courteous Staff 2.6
  • Currently 2.6 of 4 stars
Accurate Diagnosis 3.0
  • Currently 3 of 4 stars
Bedside Manner 3.0
  • Currently 3 of 4 stars
Spends Time with Me 3.0
  • Currently 3 of 4 stars
Follows Up After Visit 3.0
  • Currently 3 of 4 stars

Specialties & Research

Dr. Dennis O'Brien, MD is board certified in Internal Medicine.

  • He has special expertise in 1 area:
  • Flu (Human Influenza)

Education & Awards

Dr. O'Brien graduated from Universite De Bordeaux Ii.


Dr. O'Brien has 1 hospital affiliations:

  • St Catherine Of Siena Medical Center 


  • French

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Additional Information
Dr. Dennis Sean O'Brien MD is a male Internist, has 30 years of experience and practices in Internal Medicine.
Where does Dr. Dennis S. O'Brien practice?
Dr. Dennis O'Brien has 2 office locations.
Dr. Dennis O'Brien practices Internal Medicine near Saint James, NY.
See Saint James Internists.