To compare efficacy of tele-Simulation-based (online) and traditional Simulation-based (onsite) training on theoretical knowledge, practical skills and satisfied domains during the COVID-19 pandemic for The Center of Excellence (COE) of a private hospital network in Thailand. MATERIALS AND METHODS: 951 participants completed four courses in 2020 either through traditional (694 participants) or tele-based trainings (257 participants) with complete data were included, theoretical knowledge before and after training was assessed by a standard multiplechoice questionnaire while skills were assessed once using tools developed by an expert and specialist facilitator in a private hospital network to fit COE specific learners' performance checklist.Satisfaction was assessed by using a Likert scale questionnaire modified from the Simulation Effectiveness Tool-Modified (SET-M) of Oregon Health and Science University (OHSU). RESULTS: The study showed most participants were female, working as nurses. 34.1% had worked for more than 7 years, and 25.5% had attended Simulation training more than 5 times. The average theoretical knowledge pre-tests and post-test scores of online training was 62.1 ± 18.9 and 82.5 ± 14.3. While the theoretical knowledge score of pre-tests and post-test of onsite training was 65.6 ± 19.0 and 79.6 ± 15.6, both were statistically significant (p < 0.0001). An evaluation of efficacies in practical skills and satistified domain in all training courses for COE either via the tele-Simulation-based training or the traditional Simulation-based training found that both methods were significantly increased. Also, the participants' satisfied outcome towards the training course was 'good' to 'very good' in every area. CONCLUSION: The outcome of the study showed that the efficacy of online based training was not lower than onsite training.