Lawrence is a Consultant Thoracic and Robotic Surgeon with practicing privileges at London Bridge Hospital and the Lister Hospital in Chelsea. His NHS practice is at Guy’s and St Thomas’ Hospitals. He trained in cardiothoracic surgery in London at The Royal Brompton and Guy’s Hospitals, and in the West Midlands. 

He offers a full range of thoracic surgical services. His main areas of expertise are in minimally invasive (key-hole) and robot-assisted surgery. He leads the advanced emphysema surgical service at Guy's and St Thomas, treating patients with both key hole and bronchoscopic techniques to improve breathlessness. He has pioneered the use of small valves to treat patients collapsed and leaking lungs.

He leads the central airways service at Guy's and St Thomas' where he works with colleagues to treat patients with some of the most complex problems of the major windpipes.

He is involved in teaching and training of medical students at King's College London, work experience students and doctors at various levels of training. 

He is on the board of the Royal College of Surgeons, advising on advancing surgical techniques particularly in robotic surgery and establishing links to surgical centres in the Far East and Africa designed to improve patient outcomes in resource-constrained countries.

He has published several papers in peer-reviewed journals on various topics in general thoracic surgery and authored many chapters in key textbooks in thoracic surgery.