Marlon Cheng Decastro, MD

4.7 out of 5 (105 Ratings)
  • Internal Medicine
Tagalog, English
St. Joseph Health Medical Group - Santa Rosa - Internal Medicine
1162 Montgomery Drive
Suite 2
Santa Rosa, CA 95405
Accepting New Patients

Primary Office

St. Joseph Health Medical Group - Santa Rosa - Internal Medicine
1162 Montgomery Drive
Suite 2
Santa Rosa, CA 95405
Get Directions
(707) 890-4100
(707) 476-2237

More Information

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

    Specialties & Education

    Primary Specialties
    • Internal Medicine
    Education & Training
    • Medical School
      University of the Philippines
    • Internship
      Nassau Univ Medical Center- East Meadow
    • Residency
      Nassau Univ. Medical Center- East Meadow
    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.
  • 29-Oct-2020
    Excellent service!
    Dr DeCastro is thoughtful, caring, professional and an excellent physician. I am grateful to be under his care.
    I dont think the doctor and I saw eye to eye on a couple of things, he said something I took offense to. Im looking for another primary care doctor.
    On time, full check up and health review. I had been to the emergency room the day before and they wanted me to see my doctor for a follow up.
    good and knowkedfeable
    32 Total Comments Page 1 2 3 4 5 6 7   Next