After graduating from Westminster Medical School, University of London, Prof. Tsang completed his cardiothoracic surgical training under Mr. Christopher Lincoln at the Royal Brompton and London Chest Hospitals. He then spent two years as a Lecturer and Research Fellow at the National Heart and Lung Institute with Professor Sir Magdi Yacoub. Prof. Tsang continued his paediatric cardiac surgical training under Dr. Roger Mee at Melbourne Children's Hospital in Australia. In 1994, he began his consultancy career at Southampton University Hospital before joining Great Ormond Street, where he has specialized in neonatal and complex infant cardiac surgery for over 20 years. Additionally, he leads adult congenital heart surgery at Barts Cardiac Centre in the City of London.

Prof. Tsang has performed surgeries in Scandinavia, Germany, and China/Hong Kong, and has led charity missions with Chain of Hope (UK) in Jamaica, Jordan, and Ethiopia. He has published over 250 peer-reviewed articles and is one of the three editors of the esteemed paediatric cardiac surgical textbook, "Surgery for Congenital Heart Defects, 3rd edition" (Stark, de Leval, and Tsang). He is a frequent speaker at both national and international conferences.