Purpose This study aims to investigate the characteristics, as well as the purpose and posts of the COVID-19 Facebook groups. Design/methodology/approach A systematic search for COVID-19 Facebook groups was conducted on June 1, 2020. Characteristics of the groups were examined using descriptive statistics. Mann-Whitney test was used to study the differences between groups. The study of the most popular groups’ posts was also carried out using the content analysis method. Findings The groups had a combined membership of 2,729,061 users. A total of 147,885 posts were received. There were about approximately 60% public groups. A high percentage of the groups (86.5%) had descriptions. The results showed a significant relationship between the groups’ description status and the number of members (p-value = 0.016). The majority of COVID-19 Facebook groups (56%) were created to meet their members’ information needs. The highest number of studied posts were related to vaccination (35.2%), followed by curfew rules (19.6%) and symptoms (10.6%). Originality/value Translating these insights into policies and practices will put policymakers and health-care providers in a stronger position to make better use of Facebook groups to support and enhance public knowledge about COVID-19.