Jonathan Zimmern | Fieldfisher
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Professional background

Professional background

I have 20 years' experience dealing with complex, high value medical negligence cases covering all areas of treatment, including birth injury, delayed diagnosis, surgical negligence, brain and spinal injury, wrongful birth,  cancer care and orthopaedic injury. I also represent clients at inquests.

I regularly act for severely brain-damaged babies, securing multi-million pound awards for their care, as well as for clients fighting difficult and complicated medical and surgical cases.

I am known for my forensic analysis of medical and legal issues in complicated cases and for being able to cut to the heart of a claim. I always fight for the very best outcome for my clients.

I have experience dealing with complicated cases of clinical negligence that overlap with pre-existing personal injury claims and am regularly instructed to take over cases mishandled by other solicitors.

I am a qualified barrister and speak at conferences to medical professionals and other lawyers. I also act for the Trustees of the vCJD Compensation Scheme, managing a compensation fund of £67.5m.

Last year, I recovered damages for my clients in excess of £39.6m. A recent career highlight has also been succeeding in the Court of Appeal in a ground-breaking and complicated case involving duty of care in a genetics case (ABC v St Georges'). Read about the case.

Awards & recognition

Awards & recognition

Chambers & Partners 2026
Jonathan really goes the extra mile to get the evidence for the clients and he has a willingness to engage with the other side. He is very good.
Chambers and Partners 2025
Jonathan is a totally dedicated professional. He is friendly and supportive, with a down-to-earth confidence. He is very intelligent with a good listening ear.
Chambers and Partners 2025
Jonathan provided a very high standard in both the detail and quality of his work and we felt well supported from the day we met him to the very end.
Chambers & Partners 2024
I felt very comfortable sharing details, thoughts and feelings with him. Combined with his expertise and professionalism, I think this makes him an extraordinary lawyer.
Chambers & Partners 2024
He's just a class act. He's very thorough, very engaged on the expert evidence side of things and understands the case properly. He produces first-rate results.
Legal 500 2024
Jonathan Zimmern is a great lawyer with huge experience.
Chambers & Partners 2023
Jonathan Zimmern is attentive and has a brilliant eye for detail.
Legal 500 2023
Jonathan Zimmern is fully prepared to take on the most ground-breaking cases. 
Chambers & Partners 2022
Jonathan Zimmern is a really good litigator.

Authored pieces

Insights Case studies
Medical team performing surgery in a modern operating room, surrounded by surgical equipment, monitors, and overhead lights; scene is tinted blue for a clinical effect.
Medical Negligence
Case Study

Negligent delay in diagnosing perforation and obstruction of colon

01.09.2025
Jonathan Zimmern and Jamie Green secured a six-figure settlement for Jude* in his claim against Ashford and St Peters Hospital NHS Trust following a delay in diagnosing and treating a bowel perforation and obstruction.
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A modern, bright medical room with advanced diagnostic machines, a computer workstation, an examination chair, and a green privacy curtain near large windows letting in natural light.
Medical Negligence
Case Study

Delayed diagnosis and treatment of recurrent breast cancer that proved fatal

25.06.2025
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A collage of spinal MRI scans showing multiple views and sections of the human spine, including cervical, thoracic, and lumbar regions, displayed in blue and black tones on a medical imaging screen.
Medical Negligence
Case Study

Multi-million-pound settlement for young girl left paralysed following incorrect spinal surgery

19.06.2025
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A person sits on a sofa, holding one knee with both hands. They are wearing blue jeans and a beige cardigan over a white shirt. The focus is on the hands and knee, suggesting discomfort or pain.
Medical Negligence
Case Study

Orthopaedic surgery claim for unsuccessful and painful knee replacement

12.03.2025
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Case Study

Failure to manage blood condition at GOSH causes teenager's death

25.10.2024
Jonathan Zimmern settled a case for a five-figure sum for a mother on behalf of her 15-year-old son.
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What others say…

Chambers & Partners 2026
Jonathan really goes the extra mile to get the evidence for the clients and he has a willingness to engage with the other side. He is very good.
Chambers and Partners 2025
Jonathan is a totally dedicated professional. He is friendly and supportive, with a down-to-earth confidence. He is very intelligent with a good listening ear.
Chambers and Partners 2025
Jonathan provided a very high standard in both the detail and quality of his work and we felt well supported from the day we met him to the very end.