Prof Cheung is a clinician specialising in paediatric cardiology, a clinical researcher and a teacher. He graduated from HKU in 1990, received his Doctorate of Medicine in 2004, became a full professor in HKU in 2007, and was awarded the Faculty Teaching Medal. He is currently Bryan Lin Professor of Paediatric Cardiology of the LKS Faculty of Medicine, University of Hong Kong.  
He provides specialist clinical service for children with heart disease at Hong Kong Children’s Hospital. His scope of research encompasses paediatric and adult congenital heart disease, acquired heart disease in children, and vascular function in health and disease in the young. He has written more than 190 peer-reviewed papers, 2 books and 10 book chapters, and delivered more than 200 invited lectures. He served as an Assistant Dean in Research and Chairman of the Board of Studies of Master of Medical Sciences programme at the Faculty of Medicine, HKU. He is Chief Editor of the Hong Kong Journal of Paediatrics, a member of the education-related committees of the Hong Kong College of Paediatricians and Medical Council of Hong Kong, and serves as an examiner of undergraduate and postgraduate professional medical examinations in Hong Kong, Singapore and Malaysia.