Abstract Background Simulation-based education has become the most important part of resident training in anesthesiology, especially during the pandemic. It allows learning the skills and the management of different situations without putting residents in risk of contamination, considering COVID-19 is highly contagious. The hypothesis was that simulation is still associated with improvement of knowledge acquisitions despite the context of the COVID-19 pandemic. Methods Residents of anesthesiology and intensive care subjected to an anaphylaxis simulation scenario. Their knowledge levels were assessed by true/false questions before and one month after the simulation session. The STAI test was used to measure anxiety levels before and after the scenario. Data were analyzed statistically using Wilcoxon and McNemar tests. Results Junior residents (< 2 years) received significantly higher scores in post-training theoretical tests compared to their pre-training scores (79.2 ± 9.6, 84.5 ± 8.2, p = 0.002, n = 21). There was no difference between pre- and post-test scores of seniors (80.2 ± 9, 81.8 ± 10.4, p = 0.3). Pre- and post-anxiety inventory scores were nearly the same and both were in the moderate group (39.8 ± 10.1, 39.3 ± 12.1, p = 0.8). Conclusion Simulation-based education improved the knowledge levels of the residents without raising anxiety levels. Thus, simulation-based training showed its value as an important tool of education during the pandemic, which needs to be further popularized for training at all institutions. Enlightening medical educators about this accomplished teaching method may lead to improved quality of medical education in developing countries and reshape how tomorrow's doctors are trained during pandemics.