Dr. Mok is currently the chief of the Division of Rheumatology, Department of Medicine, Tuen Mun Hospital, Hong Kong. He is a consultant physician and honorary teaching professor of the Chinese University of Hong Kong. Dr. Mok serves as the program director of the Rheumatology / Immunology accreditation board of the Hong Kong College of Physicians.

Dr. Mok is currently the senior associate editor of the International Journal of Rheumatic Diseases and an editorial member of the Journal of Rheumatology, Current Rheumatology Review, Open Orthopedic Journal and Immunology and Immunogenetic Insights. In addition, he is an ad-hoc reviewer of more than 60 medical and rheumatology journals. Dr. Mok is a Past President of the Hong Kong Society of Rheumatology. He is the founder editor of the Hong Kong Bulletin on Rheumatic Diseases, the official publication of the Hong Kong Society of Rheumatology.