IntroductionMany healthcare systems initiated rapid training with COVID-19 simulations for their healthcare workers (HCWs) to build surge capacity and optimize infection control measures. This study aimed to describe COVID-19 simulation drills in international healthcare centers. MethodsThis is cross-sectional, international survey among simulation team leaders and HCWs, based on each centers debriefing reports from simulation centers from 30 countries in all WHO regions where COVID-19 simulation drills were conducted. The main outcome measures were the COVID-19 simulations characteristics, outcomes, facilitators, obstacles and challenges encountered during the simulation sessions. ResultsInvitation was sent to 500 simulation team leaders and HCWs, 343 responded, and 121 completed the survey. Those who completed the study were from East Mediterranean (EMRO) countries (41.3%); Southeast Asian countries (SERO) (25.6%); and Europe (12.4%) and the remainder from other regions. The frequency of simulation sessions was monthly (27.1%), weekly (24.8%), twice weekly (19.8%), or daily (21.5%). Among participants, 55.6% reported teams full engagement in the simulation sessions. The average session length was 30-60 minutes. The most commonly reported debriefing leaders were ICU staff, simulation lab staff, and ER facilitators, and the least common were infection control staff. A total of 80% reported "a lot" to "a great improvement" in terms of clinical preparedness after simulation sessions, and 70% were satisfied with the COVID-19 simulation sessions and thought they were better than expected. Most of the perceived issues reported were related to infection control measures, followed by team dynamics, logistics, and patient transport issues. ConclusionSimulation centers team leaders and HCWs reported positive feedback on COVID- 19 simulation sessions. The presence of multiprofessional personnel during drills is warranted. These drills are a valuable tool for rehearsing safe dynamics of HCWs on the frontline of COVID-19. Summary boxexplaining the significance of their study by providing each of the following key questions What is already known?O_LISimulation enhances healthcare systems safety. C_LIO_LIPreparedness to potential disasters includes training for personal protection techniques, environmental contamination, medical management, and training of HCWs. C_LI What are the new findings?O_LIMany hospitals conducted COVID-19 simulations in all WHO regions. C_LIO_LIMost of the team leaders and HCWs reported full engagement and significant clinical preparedness improvement after the COVID-19 simulation sessions. C_LI What do the new findings imply?O_LIThe presence of multiprofessional personnel, including infection control experts, during COVID-19 drills is warranted. C_LIO_LISimulation are a valuable tool for rehearsing safe dynamics of HCWs on the frontline of COVID-19. C_LI