We report on conducting online exams for Year Two medical students. These are closed-book exams of three major courses scheduled on different dates. Each exam comprised 2-3 papers [MCQ, SAQ and practical (mostly with images requiring short answers)] and each paper lasted 60-90 min. Students took the exam under Blackboard (CUHK/China) using LockDown Browser/Respondus Monitor together with “Zoom” live invigilation/video recording. Students were well informed of the exam arrangement, provided with troubleshooting guides, required to attend two mock exams and given unlimited access to practice test site. Fourteen students opted to take online exams back on campus due to poor internet connectivity or unfavourable environment at home. 234 students (four in Mainland) were divided into ten “Zoom” groups to facilitate invigilation and to stagger their time of activating the LockDown Browser and starting the exam under Blackboard. Students were pre-assigned to join four separate but identical online exams to avoid overloading a single test site. For MCQ, we adopted a single randomization of options and allowed backtracking. In the first and a half day of exams, 15 and 28 students experienced difficulties with LockDown Browser or early exit from exams. For the remaining exams, we switched to release MCQ and practical exam questions all at once instead of one by one, and students encountering difficulties dropped to 2-3. In conclusion, we could work on the exam setting and avoid concurrent exams with other major programmes, while random errors with servers and devices used for taking online exams are beyond control.