Dr. Thomas Diamant, MD | Costa Mesa, CA | Pulmonology

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Dr. Thomas Diamant is a pulmonologist who brings nearly five decades of medical experience to his practice in Costa Mesa, California. He earned his medical degree from McGill University Faculty of Medicine and completed his residency training at Toronto General Hospital. With 47 years of dedicated practice, Dr. Diamant has developed extensive expertise in treating respiratory and lung conditions. He provides care in English for patients seeking specialized pulmonary treatment.

Dr. Diamant practices at Hoag Hospital Newport Beach and sees patients in Costa Mesa. His clinical focus includes treating asthma in both adult and pediatric patients, as well as managing rhinitis and other respiratory conditions. He performs essential diagnostic procedures such as pulmonary function testing and bronchodilator reversibility testing to evaluate lung health. Dr. Diamant also conducts newborn pulse oximetry screening to ensure proper oxygen levels in infants.

AI-generated from data on this provider profile.

2.1

9 Ratings
47 years of experience
31 insurance plans accepted
speaks English
Toronto General Hospital
8 written reviews
1 specialty
7 areas of expertise
1 board certification
1 hospital affiliation
2 office locations
Male

Flexible scheduling

Based on patient feedback. Read the reviews

Dr. Diamant's Ratings and Reviews

2.1

9 Ratings with 8 written Reviews

Average Wait Time 20 Minutes

How was your appointment with
Dr. Diamant?

Patients’ Perspective

Gave an accurate diagnosis: (3) Did WellNeeds Improvement (4)
Had a good bedside manner: (3) Did WellNeeds Improvement (3)
Spent time with me: (4) Did WellNeeds Improvement (3)
Provided follow-up after the visit: (3) Did WellNeeds Improvement (3)
Flexible scheduling: (5) Did WellNeeds Improvement (2)
Saw me in a timely manner: No Ratings
Staff was courteous: No Ratings

9 ratings & reviews

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Showing 1 to 8 of 8 reviews

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The staff were warm and caring. Dr. Diamant however lacked compassion and was condenscending, almost sneering. I felt like I was the least important part of his day.

April 17th, 2026

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Dr Diamant showed no compassion and did not care about patients' concern. The staff was equally rude and condescending. I will never come back.

December 3rd, 2022

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How does he even have 2 stars! It has taken me a long time to write this. He had no compassion no interest in helping his patients. In a hurry and rude. He told me I will end up in the hospital w a life threatening asthma attack. Thank goodness I found a decent pulmonologist and don’t ha. To deal with this person

September 14th, 2022

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No bedside manner. Talks over you. Don’t listen when he asks questions! He kept complaining “ why I don’t have all the paperwork, although all the results is in the website! He is rude. Never, ever want to mention his name again.

December 11th, 2021

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Stay away from this Dr. He has anger issues and does not care what you have to say. I've NEVER had such a rude doctor.

April 19th, 2018

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He is a exceptional Dr. He saved my life. I was a long time patient of his and due to my insurance change I could no longer continue with him. I would highly recommend him to anyone that suffers from Pulmonary diseases.

October 20th, 2015

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This dr. Has a temper I would not see him!

July 20th, 2012

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Dr Diamant and his staff were thorough and displayed genuine concern for me during all office visits and testing. I highly recommend them.

April 4th, 2010

Dr. Thomas Diamant

136 BroadwayCosta Mesa, CA 92627

Tel: (949) 873-5537

College Hospital Costa Mesa

301 Victoria StCosta Mesa, CA 92627

Tel: (949) 642-2734


Dr. Thomas Diamant, MD	Dr. Asad Javed, MD	Dr. George Shahinian, MD	Dr. Ettayapuram V Sunderrajan, MD
Pulmonology	Pulmonology	Pulmonology	Critical Care Medicine
	Accepts New Patients		Accepts New Patients
2.1 (9 Ratings)	5 (2 Ratings)	4.8 (26 Ratings)	3 (4 Ratings)
47 Years of Experience		30 Years of Experience	57 Years of Experience
No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option	No Virtual Visit Option
Speaks English	Speaks English, Hindi, Urdu	Speaks English, Spanish	Speaks English, Spanish
Costa Mesa , CA	Orange , CA	Laguna Beach , CA	Fountain Valley , CA
Med School: Mc Gill Univ Fac Of Med		Med School: St Georges University School Of Medicine	Med School: Andhra Medical College
Current Profile	View Profile	View Profile	View Profile

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Pulmonology

Angiographic Visualization
Asthma
Chest Infection
Chronic Obstructive Pulmonary Disease (COPD)
Emphysema
Pneumonia
Tuberculosis (TB)

MEDICAL LICENSE

Medical Doctor, California, 2026, Active

EDUCATION & TRAINING

Residency

Toronto General Hospital

Medical School

Mc Gill Univ Fac Of MedGraduated in 1979

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Where is Dr. Thomas Diamant's office located?: Dr. Thomas Diamant's office is located at 136 Broadway, Costa Mesa, CA, 92627.
What languages does Dr. Thomas Diamant speak?: Dr. Thomas Diamant speaks English.
Does Dr. Thomas Diamant accept virtual/telehealth appointments?: Dr. Thomas Diamant has not indicated that they accept virtual/teleheatlh appointments. Contact their office through their Vitals profile to check for availability.
Is Dr. Thomas Diamant accepting new patients?: Dr. Thomas Diamant has not indicated that they accept new patients. Contact their office through their Vitals profile to check for availability.
Does Dr. Thomas Diamant accept my insurance?: You can see the insurance plans that Dr. Thomas Diamant accepts on their Vitals profile.

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