Purpose: Increased workload and inadequate working conditions during the COVID-19 pandemic, threaten the lives and physical well-being of healthcare workers (HCWs), and also their mental health, such as burnout, etc. which is often neglected. The aim of this review is to analyze published studies on the proportion of burnout among HCWs during the first wave of the COVID-19. Materials and Methods: We conducted a systematic review of studies that reported burnout (measured by Maslach Burnout Inventory) among HCWs during the COVID-19 pandemic and searched PubMed, PsycINFO, and WOS of relevant articles up to Feb 25th, 2021. Out of 145 non-duplicate studies, 10 were included in the meta- analysis. Results: The overall estimated pooled proportion for emotional exhaustion (EE) was 31% (95% CI: 24%-40%), for depersonalization (DP) was 28% (95% CI: 23%-38%) and 22% (95% CI: 13%-34%) for personal accomplishment (PA). The results show that in countries where the number of cases is high and the number of beds and doctors is low, the level of EE appears to be slightly lower and PA is slightly higher. However, there were no significant differences according to subgroup analyses. Conclusion: Evidence from early studies highlight the fact that a significant proportion of HCWs suffers from burnout during this pandemic. It will be necessary to pay close attention to HCWs' mental health and identify ways to reduce risks and prepare a rehabilitation program for the HCWs during and after the pandemic.