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Dr Nikolaos Diamantis

MD, MRCP, PhD

Oncologist

22 years of experience

London, NW8 7JA

(+3 more)

11 connections in healthcare

Skill endorsed

by Dr Dionysis Papadatos-Pastos, Professor Bijendra Patel and 1 other professional

4.97

/5

(20 reviews)

22 years of experience

London, NW8 7JA

(+3 more)

11 connections in healthcare

Skill endorsed

by Dr Dionysis Papadatos-Pastos, Professor Bijendra Patel and 1 other professional

Areas of expertise

All
Reviews
Skill Endorsements
Chemotherapy
10
Colorectal Cancer
8
1
Bowel Cancer
5
1

Contact

Book


Expert in:

About Dr Nikolaos Diamantis

Dr Nikos Diamantis is a Medical Oncology Consultant at St Bartholomew's Hospital specialising in colorectal, oesphageal, gastric, pancreatic, liver and bile duct cancers, and cancers of unknown primary. He is the Barts Trust Lead for Acute Oncology and Cancer of Uknowon Primay.

Dr Diamantis underwent specialist training at the Imperial College Healthcare Hammersmith, St Mary's and Harefield Hospitals. He was awarded the Greek national Oncology fellowship scholarship and went on to conduct clinical research for 2 years at the Drug Development Unit of the Royal Marsden.

Research interests include immunotherapy for GI malignancies and first in human clinical trials. Dr Diamantis is a Principal Investigator for a number of Phase 2 and 3 trials.



.


Subspecialties

  • Medical Oncology

Areas of expertise

All
Reviews
(35)
Skill Endorsements
(8)

Click the bar to read reviews or skill endorsements

Chemotherapy
10
Colorectal Cancer
8
1
Bowel Cancer
5
1
Pancreatic Cancer
2
Cancer Prevention and Screening
2
Cancer of Unknown Primary
2
Neoadjuvant
2
Colon Cancer
1
Hernia
1
Adenocarcinoma
1
Gastroenteritis
1
Appendicitis
1
Gastrointestinal Cancers
1
Liver Disease
1
Bile Duct Cancer (Cholangiocarcinoma)
1
Liver Metastases
1
Histotripsy
1
Biliary Cancer
Carcinoma of Unknown Primary
Clinical Trials
Gallbladder Cancer
Immunotherapy
Oesophageal Cancer
Oligometastic Disease
Rectal Cancer
Small Bowel Cancer
Stomach (Gastric) Cancer
Targeted Therapy
Video Consultation

Registered with

General Medical Council

No. 7013255


Education

University of Athens

Medicine

Graduated 2004


Qualifications

MRCP (UK) Medical Oncology 2015

Medical Oncology Board Exams 2015

ESMO Medical Oncology Certificate 2014

MRCP (London, UK) 2012

PhD with Honors - University of Athens 2010

MD - Ptychio Iatrikes with merit, National and Kapoditstrian University of Athens, Greece, 2004


Languages spoken

  • English

Fees

  • New appointment

    £350
  • Follow-up appointment

    £250
*May vary on location

Locations

HCA Healthcare UK The Wellington Hospital Outpatients

15-17 Lodge Road, London, United Kingdom, NW8 7JA

4.73(2,770 reviews)

Opening hours

Monday
Tuesday
Wednesday
Thursday
10:00 - 12:00
Friday
Saturday
Sunday

Facilities

Paid Parking
View practice profile

Opening hours

Monday
Tuesday
Wednesday
Thursday
10:00 - 12:00
Friday
Saturday
Sunday

Facilities

Paid Parking
View practice profile

HCA Healthcare UK The Wellington Hospital

8A Wellington Place, St Johns Wood, London, United Kingdom, NW8 9LE

4.68(3,164 reviews)

Opening hours

Monday - Friday
Saturday
Sunday

Facilities

Paid Parking
View practice profile

HCA Healthcare UK The Harley Street Clinic

35 Weymouth Street, London, United Kingdom, W1G 8BJ

4.75(3,301 reviews)

Opening hours

Monday - Friday
Saturday
Sunday

Facilities

Paid Parking
View practice profile

Cromwell Hospital

164-178 Cromwell Rd, London, United Kingdom, SW5 0TU

4.87(1,939 reviews)

Opening hours

Monday - Friday
Saturday
Sunday

Facilities

Wheelchair Accessible
Paid Parking
View practice profile

Areas of expertise

All
Reviews
Skill Endorsements
Chemotherapy
10
Colorectal Cancer
8
1
Bowel Cancer
5
1

Contact

Book

Reviews

5
verified patient
21 Jul 2026

Excellent and outstanding support

Patient seen for:
5
verified patient
18 Jul 2026

My husband and I saw Dr Diamantis to ask about getting treatment for my husband's esophagal cancer. since we have only recently arrived in England andhave no previous Sevious experieance of the National Health Service. this was proving difficult. Dr Diamanatis was quick to understand our difficulty, ofered reassuring advice, and promised to f=give us such help as he could to access the system. We are most grateful and hope for the best.

Patient seen for:
5
verified patient
17 Jul 2026

Having a consultation on Monday the process from everyone has been highly efficient from initial enquiry through to booking

5
verified patient
13 Jul 2026

I received exceptional care from Dr. Diamantis, among others, in my recent inpatient visit

5
verified patient
12 Jul 2026

Dr Diamantis is caring, approachable, and highly knowledgeable. You feel safe in his care and appreciate that he takes the time to thoroughly explain treatment plans ensuring that you fully understand what is proposed. He is happy to answer all your questions and you don’t feel rushed. You are in good hands which brings immense comfort during highly stressful cancer treatments. I highly recommend him.

5
verified patient
24 Jun 2026

Doctor with principles, professional and honest.

Patient seen for:
5
verified patient
19 Jun 2026

We have been under the care of Dr. Diamantis for colorectal cancer with liver metastasis and cannot recommend him highly enough. From our very first meeting, he has been warm and reassuring during a frightening time. He truly listens, taking our wishes into account at every stage of treatment rather than simply dictating a plan. He explains complex medical details carefully and clearly, never making us feel rushed. Above all, his clinical expertise is exceptional. We must also mention his secretary who has been absolutely outstanding. The value of a brilliant secretary in private healthcare is so easily underestimated, yet it makes all the difference — replying to emails promptly, booking in scans, and keeping everything running smoothly and stress-free.

5
verified patient
21 Apr 2026

Dr Diamantis is thorough, caring, friendly and extremely good at tailoring explanations (of scans, treatments etc) to my level of interest and understanding. He is generous with his limited time and very thoughtful when it comes to planning treatment around other life events.

5
verified patient
01 Apr 2026

Dr Diamantis was the perfect choice for us. We wanted a second opinion and he listened well, was very knowledgable and gave clear answers and direction. He had a very human approach and we felt comfortable to ask everything we needed. We left the consultation more confident about the upcoming treatement and the decisions we made.

Patient seen for:
5
verified patient
31 Mar 2026

Very nice and excellent doctor. Explains everything clearly.

Patient seen for:
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Skill Endorsements

Nikos is a valued colleague and a knowledgeable clinician to whom I confidently refer patients.

19 Jun 2025
Endorsed for
Neoadjuvant
Cancer Prevention and Screening
Colorectal Cancer

Dr Dionysis Papadatos-Pastos

Dr Dionysis Papadatos-Pastos

Oncologist
We trained together

Dr Nikolaos Diamantis is an outstanding oncologist whose clinical expertise and compassionate care make a real difference to his patients. He combines scientific precision with genuine empathy and professionalism.

22 May 2025
Endorsed for
Hernia
Appendicitis

Professor Bijendra Patel

Professor Bijendra Patel

General Surgeon
I have referred patients to them

30 Dec 2024
Endorsed for
Neoadjuvant
Cancer Prevention and Screening
Bowel Cancer

Mr Yazan Masannat

Mr Yazan Masannat

Breast Surgeon
Is a colleague

FAQ

What are Dr Nikolaos Diamantis's reviews like?

Dr Nikolaos Diamantis's overall patient rating is 4.97 out of 5 stars on Doctify. This is based on 20 reviews.

What languages does Dr Nikolaos Diamantis speak?

Dr Nikolaos Diamantis speaks English

Where is Dr Nikolaos Diamantis located?

Dr Nikolaos Diamantis primarily practices at HCA Healthcare UK The Wellington Hospital Outpatients, located at 15-17 Lodge Road, London, United Kingdom, NW8 7JA
See more locations

What are Dr Nikolaos Diamantis working hours?

Dr Nikolaos Diamantis is working Thursday (10:00 - 12:00)

Find where Dr Nikolaos Diamantis operates today

Does Dr Nikolaos Diamantis accept new patients?

Dr Nikolaos Diamantis generally accepts new patients.

Get in touch with this specialist to enquire as a new patient