Dr. Mark A. Walshauser, MD | O Fallon, IL | Oncology

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Dr. Mark Walshauser specializes in oncology, bringing two decades of experience to cancer care. He earned his medical degree from Ross University School of Medicine and completed his residency at St. Louis University School of Medicine. Dr. Walshauser speaks English and has dedicated his career to helping patients navigate cancer treatment with expertise and compassion.

Dr. Walshauser practices at multiple locations across Illinois, including O'Fallon and Highland, with affiliations at HSHS Saint Elizabeth's Hospital, HSHS Saint Joseph's Hospital Highland, and several other medical centers. He treats patients with various forms of cancer, including lung cancer and non-small cell lung cancer. His practice also includes managing conditions like iron deficiency anemia that can accompany cancer treatment. Patients rate Dr. Walshauser an average of 3.1 out of 5 stars for his care.

AI-generated from data on this provider profile.

accepting new patients
3.1

7 Ratings
20 years of experience
speaks English
St Louis University School Of Medicine
6 written reviews
1 specialty
8 areas of expertise
1 board certification
6 hospital affiliations
6 office locations
Male

7 ratings & reviews

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Showing 1 to 6 of 6 reviews

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If I could give him less starts I would. He didn't even ask my symptoms and didn't spend more than 5 minutes in the room with me before dismissing me. He not only dismissed me, but put me down during our consult. I have never been more frustrated in my life. He has HORRIBLE bedside manor and should not be a physician.

September 29th, 2025

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Little bit of a wait but worth it!

June 5th, 2018

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I first met Dr W when I was hospitalized. He came to visit me several times and help me understand the issue and plan forward. I have had many procedures and follow ups. Occasionally they are very busy with emergencies and my wait time was long. He apologized for the long wait. He noticed I was nervous but his calming demeanor made me relax. He explained the results of my tests and made sure I understood everything. I really liked him and will continue my doctoring with him.

April 8th, 2018

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Saw my mother for a new diagnosis of breast cancer. Answered her questions in a direct but honest and easy to understand manor. Explained options. Gave her reassurance that he would support any decision she made. I am a certified oncology RN and have many years of experience. It is different seeing the process from this side of the "bed". He went out of his way to make BOTH of us comfortable.

February 25th, 2018

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Refuses to listen to patients about treatment that can't be performed wothout massive damage. Is this more about money???

November 28th, 2017

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A very poor doctor he never really looked in to all my medical issues. Provided poor care and never explained anything. He even failed to keep me on my blood thinners that I need for life my primary doctor had to do that. My medical history is terrible I'm sure he's in the dark.

October 27th, 2017

Cancer Care Center Of Ofallon

321 Regency ParkO Fallon, IL 62269

Tel: (618) 416-7970

Mon8:00 am - 4:30 pm

Tue8:00 am - 4:30 pm

Wed8:00 am - 4:30 pm

Thu8:00 am - 4:30 pm

Fri8:00 am - 4:30 pm

SatClosed

SunClosed

Cancer Care Specialists Of Illinois

12860 Troxler Ave Ste 135Highland, IL 62249

Tel: (618) 651-2888

MonClosed

TueClosed

WedClosed

Thu8:00 am - 4:30 pm

FriClosed

SatClosed

SunClosed

Hshs Saint Josephs Hospital Highland

12866 Troxler AveHighland, IL 62249

Tel: (618) 654-7421

Sparta Community Hospital

818 E Broadway StSparta, IL 62286

Tel: (618) 443-2177

Hshs Saint Elizabeths Hospital

1 Saint Elizabeth BlvdO Fallon, IL 62269

Tel: (618) 234-2120

Memorial Hospital Shiloh

1404 Cross StO Fallon, IL 62269

Tel: (618) 607-1000


Dr. Mark Andrew Walshauser, MD	Dr. Arslan Babar	Dr. Gordon Bruce Gale, MD	Dr. Susan L Hays
Oncology	Hospice & Palliative Medicine	Diagnostic Radiology	Nurse Practitioner
Accepts New Patients	Accepts New Patients	Accepts New Patients	Accepts New Patients
3.1 (7 Ratings)	0 (0 Ratings)	4 (1 Rating)	0 (0 Ratings)
20 Years of Experience	12 Years of Experience	50 Years of Experience
No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option
Speaks English		Speaks English	Speaks English
O Fallon , IL	Saint Louis , MO	Saint Louis , MO	Saint Louis , MO
Med School: ROSS UNIVERSITY SCHOOL OF MEDICINE	Med School: Shifa College Of Medicine	Med School: St Louis University School Of Medicine
Current Profile	View Profile	View Profile	View Profile

Search for your insurance and plan

Accepts Medicare
Accepts Medicaid

Oncology

Blood Cancer
Bone Marrow Transplant
Chemotherapy
Hodgkin's Lymphoma
Leukemia
Lymphoma
Myelofibrosis
Myeloma

MEDICAL LICENSE

Medical Doctor, Illinois, 2026, Active

EDUCATION & TRAINING

Residency

St Louis University School Of Medicine

Medical School

ROSS UNIVERSITY SCHOOL OF MEDICINEGraduated in 2007

Ross University School Of MedicineGraduated in 2006

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Is Dr. Mark Walshauser accepting new patients?: Dr. Mark Walshauser is accepting new patients on Vitals. View Dr. Mark Walshauser's profile on Vitals to make an appointment.
Does Dr. Mark Walshauser accept my insurance?: You can see the insurance plans that Dr. Mark Walshauser accepts on their Vitals profile.
Which hospitals is Dr. Mark Walshauser affiliated with?: Dr. Mark Walshauser is affiliated with Hshs Saint Elizabeths Hospital, Hshs Saint Josephs Hospital Highland, Sparta Community Hospital, Memorial Hospital Shiloh, Hshs Saint Josephs Hospital Breese, and HSHS HOLY FAMILY HOSPITAL.
Where is Dr. Mark Walshauser's office located?: Dr. Mark Walshauser's office is located at 321 Regency Park, O Fallon, IL, 62269.
What languages does Dr. Mark Walshauser speak?: Dr. Mark Walshauser speaks English.

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