The paper investigates participation and engagement during an online medical education conference by examining delegate interactions in the parallel chat function of the video platform. Although much is known about the experiential nature of online conferencing, we know far less about what actually happens in the live unfolding chat itself. We collected 813 unique messages from the parallel chat of an online conference. Speakers presented from a ‘digital backstage’ to the ‘Main Stage’ while delegates watched and chatted. We used descriptive statistics to summarize message/chat content in terms of participant categories (conference team member, speaker, or delegate, gender) and topic. We also developed a coding scheme based on the conversation analysis to understand the interactional function of messages and their connectedness to other messages. Overall, 23% of delegates participated in the chat, mostly commonly posting positive assessments (“Wonderful talk!”) and appreciations (“Thank you!”). Other actions included questions and answers, agreement, information-giving, statements, and suggestions. Qualitative analysis provided insights into how participants engaged directly with Main Stage presentations. We suggest that to better understand engagement in video conferencing, analysis should focus on actual participation and its content, rather than (or at least supplementary to) post-hoc reports and surveys. Data are in British and Australian English.