Marlon DeCastro, MD

4.8 out of 5 (112 Ratings)
  • Internal Medicine
Additional Language Spoken
Internal Medicine – Doyle Park Suite 303
500 Doyle Park Dr.
Suite 303
Santa Rosa, CA 95405

Primary Office

Internal Medicine – Doyle Park Suite 303
500 Doyle Park Dr.
Suite 303
Santa Rosa, CA 95405
Get Directions
(707) 303-8300
(707) 303-8301

More Information

Medical Groups & Affiliations
  • St. Joseph Health Medical Group
  • Meet The Doctor

    Specialties & Education

    Primary Specialties
    • Internal Medicine
    Education & Training
    • Medical School
      University of the Philippines- Manila, Philippines
    • Internship
      Nassau Univ Medical Center- East Meadow, NY
    • Residency
      Nassau Univ. Medical Center- East Meadow, NY
    Areas of Interest
    Family Medicine, General Practice, Internal Medicine
  • Biography


    As an internist, Dr. DeCastro specializes in providing patient-centered care for adults of all ages. He is board certified in Internal Medicine and able to care for an individual's specific medical needs from preventive services to the diagnosis, treatment and management of acute and chronic conditions and diseases. He is especially adept at treating individuals with diabetes.

    Dr. DeCastro received his medical degree from the University of the Philippines in Manila, and conducted an Internal Medicine residency at Nassau University Medical Center in East Meadow, New York. Most recently, Dr. DeCastro served as an attending physician at Clemson Health Center in South Carolina where he provided primary care to adults and served as lead investigator in several studies. While there, he also earned certification in the Diabetes Physician Recognition Program, presented by the National Committee for Quality Assurance.
  • 4-Feb-2019
    *Dr. DeCastro was not quite sure why I had been requested to come in the office? I was ultimately charged for office visit, not sure I needed one?
    10. Not enough experience with him.
    *Dr. DeCastro is the best doctor I've had! Feel very lucky to be in his care.
    I have had a skin-rash problem for a long time. Nothing seems to cure me, so I gave up and I didn't even mention it. Doctor asked, "No swelling in your feet," as he lower my sock. He said: "Oh, you have dry skin." He said nothing else, I didn't say anything else, and he left the examining room. So, it was my fault not to be checked for the problem...again.
    Very satisfying.
    14 Total Comments Page 1 2 3   Next