MA(Cantab) MB BChir PhD FRCP
27 years of experience
London, W1G 6BW
(+3 more)
41 connections in healthcare
Skill endorsed
by Dr Apostolos Koffas, Dr Alan Watson and 16 other professionals
27 years of experience
London, W1G 6BW
(+3 more)
41 connections in healthcare
Skill endorsed
by Dr Apostolos Koffas, Dr Alan Watson and 16 other professionals
Areas of expertise
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Please be aware that during the COVID-19 outbreak Dr Kallis will be undertaking face-to-face consultations if required. Video and telephone consultations are also available, please contact for further information.
Dr Yiannis Kallis is a Consultant Hepatologist and Gastroenterologist at the Royal London Hospital (Barts Health NHS Trust) and the Royal Free Hospital London, two of the UK's leading teaching hospitals, where his practice covers a broad range of gastro-intestinal diseases. He specialises in liver disease and disorders of the pancreas and bile ducts, and runs the NE London outreach liver transplant network. He has been Clinical Lead for Hepatology at the Royal London Hospital and Network Director for Hepatology across NE London integrated care service.
He is a highly skilled in diagnostic and therapeutic endoscopy and colonoscopy, with a particular expertise in complex ERCP (endoscopy of the bile duct and pancreatic duct). He has been at the forefront of research into developing novel endoscopic treatments for pancreato-biliary cancers, and is a specialist advisor to the National Institute of Health and Care Excellence (NICE) in this field. He has served on the British Society for Gastroenterology (BSG) liver committee and the British Liver Transplant Group committee.
He graduated from Cambridge University with Distinction and undertook postgraduate specialty training across several leading London teaching hospitals. He was awarded a PhD in 2010 for his research into liver fibrosis, stem cells and regeneration at Imperial College London and Cancer Research UK, and publishes his work in high impact peer-reviewed journals.
He is currently an Honorary Clinical Senior Lecturer at Barts and the London School of Medicine and Dentistry, QMUL, where he is a principal investigator on several multi centre clinical trials in treatments for advanced liver disease and for inflammatory disorders of bile ducts. He regularly lectures in gastroenterology and hepatology and supervises MSc student projects in liver disease at QMUL. He sits on the writing group for national guidelines in liver disease.
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General Medical Council
No. 4583211
University of Cambridge
Medicine
Graduated 1998
New appointment
£350Follow-up appointment
£25020 Devonshire Place, London, United Kingdom, W1G 6BW
Pond Street, London, United Kingdom, NW3 2QG
17 Harley Street, London, United Kingdom, W1G 9QH
Consulting Rooms UME Health, 17 Harley St, London, United Kingdom, W1G 9QH
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This summary was created by AI based on recent reviews
Dr Yiannis Kallis is clear, professional, kind, and reassuring with patients. He offers thorough explanations of diagnoses and procedures like gastroscopy, ERCP, and liver scans. Dr Kallis listens to patient concerns and ensures comfort, building trust. His expertise includes FibroScan procedures, vital for patient assessment.
I was reassured I am in good hands by Dr Kallis' expertise which became obvious from the first consultation. Very clear explanations in easy to understand terms about tests he was planning to request, result interpretation and decisions about next steps, decisions in which he involved me, taking into account my input and preferences. Many thanks for carefullylistening to my symptoms.
I found Dr Kallis to be very professional, through and highly knowledgeable. He is easy to talk with and takes his time answering any queries. I would be happy to consultant with him in future.
Didn’t bother at all and no concern for the severity of symptoms following regular basic testing. Ignorant of daily struggle
I got an appointment within a few days and was very pleased with my consultations.
I had three appointments. Overall, the level of professionalism was ok, but I thought the patient care was somewhat subpar for a private provider.
I have found Dr Kallis an excellent Dr. He has been very clear in his advice and seems to be very thorough in his investigation. He is also very pleasant to deal with. He doesn't mind being asked lots of questions, which I find very reassuring.
Dr Kallis explained in detail my condition and the next steps regarding tests. His calm manner and detailed explanations were very reassuring.
Dr Kallis is an excellent clinician who combines strong clinical expertise with genuine dedication to patient care. They consistently go above and beyond for their patients and are committed to achieving the best possible outcomes.
28 May 2026
Dr Apostolos Koffas
GastroenterologistAn excellent and skilled liver specialist that I have known and worked with for many years. I have no hesitation in endorsing him.
17 Apr 2026
Dr Alan Watson
GastroenterologistDr Kallis is a very knowledgeable and experienced hepatologist and interventional endoscopist incl. gastroscopies, colonoscopies and ercp. He is very empathetic and patient-focussed in his approach.
25 Jun 2025
Dr. Constantinos Parisinos
GastroenterologistDr. Kallis is an expert gastroenterologist specialising in hepatology and the management of pancreaticobiliary diseases. Highly skilled in complex ERCP, he combines technical proficiency with compassionate patient care, providing exceptional service to patients.
27 Oct 2024
Dr. Ricardo Jose
Respiratory Doctor
Explore videos from Dr Yiannis Kallis explaining process of procedures and other important things you should know before choosing your provider.

Curious about fatty liver and how to tackle it? Join Dr. Yiannis Kallis as he shares his expert knowledge on the causes, symptoms, treatments, and risks of t...
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Consultant Hepatologist and Gastroenterologist Dr. Yiannis Kallis explains what an ERCP (Endoscopic Retrograde Cholangiopancreatography) procedure is, why it...
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Ever wondered how doctors investigate gut problems? Join Dr Yiannis Kallis as he explains what an endoscopy is, how this procedure can diagnose conditions li...
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Ever wondered about gallstones and how they affect your health? Join Dr Yiannis Kallis, a specialist gastroenterologist and hepatologist, as he explains the ...
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Dr. Yiannis Kallis, consultant hepatologist and gastroenterologist at Nuffield Health, explains what liver function tests (LFTs) are, why they are performed,...
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What are Dr Yiannis Kallis's reviews like?
Dr Yiannis Kallis's overall patient rating is 4.93 out of 5 stars on Doctify. This is based on 334 reviews.
What languages does Dr Yiannis Kallis speak?
Dr Yiannis Kallis speaks English
Where is Dr Yiannis Kallis located?
Dr Yiannis Kallis primarily practices at The London Clinic, located at 20 Devonshire Place, London, United Kingdom, W1G 6BW
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What are Dr Yiannis Kallis working hours?
Dr Yiannis Kallis is working Monday (09:00 - 15:00, 15:00 - 18:00), Friday (09:00 - 12:30, 17:00 - 19:00)
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Does Dr Yiannis Kallis accept new patients?
Dr Yiannis Kallis generally accepts new patients.
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