Professor Leung is currently the Li Shu Fan Medical Foundation Professor in Gastroenterology, Chief Director of the Clinical Trials Centre and the Associate Dean (Research) of the Li Ka Shing Faculty of Medicine of the University of Hong Kong. Professor Leung graduated from the Chinese University of Hong Kong and completed his residency and fellowship at the Prince of Wales Hospital of Hong Kong and Division of Gastroenterology, Baylor College of Medicine, USA. 

Professor Leung has a wide research interest in gastroenterology and endoscopy including Helicobacter pylori and gastric carcinogenesis, inflammatory bowel disease, capsule endoscopy, and advanced endoscopy. He has published more than 300 original articles with a h-index of 70 (Scopus). He is the editorial board member of the Endoscopy, Helicobacter, and Journal of Digestive Disease. He is the current President of the Hong Kong Society of Gastroenterology (2022-2024).