Introduction: Work-related mental disorders are frequent and affect not only the work activity, but also the individual’s quality of life. During the COVID-19 pandemic – which began in 2019, there were changes in terms of society’s behavior in relation to its work activity – such as social isolation and teleworking – which brought uncertainties in the work dynamics of most professionals and functioned as one of the factors that influenced the emergence of mental disorders in the Brazilian population.(1) In this context, the importance of assessing the prevalence of these disorders in a pre- and post-pandemic comparison is evident. Material and method: Descriptive, cross-sectional study through data collection using the DATASUS platform, using available data for the years 2018 to 2021. Objective: To describe the annual prevalence of work-related mental disorders in Brazil, from the comparison data for the years 2018 to 2021. In addition, expose whether there was an increase in prevalence in the year of the beginning of the pandemic (2019), in relation to the pre-pandemic period (2018), and if the upward trend persisted with regard to the pandemic period (2019 and 2020) and post-pandemic period (2021). Results: Between 2018 and 2021, there were a total of 7337 cases. Of these, 1812 (24.7%) were registered in 2018, 2378 (32.4%) in 2019, 1343 (18.3%) in 2020 and 1804 (24.6%) in 2021. Thus, comparing by periods: from 2018 to 2019, cases increased from 1812 to 2378, which represents a percentage increase of 31.2%. From 2019 to 2020, the registered numbers fell by 43.5%, and from 2020 to 2021, a new increase corresponding to 34.3% was observed. Discussion: This analysis showed that the highest percentage increase occurred from 2020 to 2021, a transition period between telecommuting and working in a physical environment. In addition, in the year of the greatest spread of COVID-19 (2019), there was also a considerable increase in the number of cases.Conclusion: of the 7,337 total cases, the year with the highest number of cases of work-related mental disorders in Brazil was 2019, when the pandemic began in the country, a factor that promoted changes in Brazilian labor dynamics. However, it was possible to conclude that the post-pandemic period (2021), in relation to the number of cases, had a similar prevalence to the pre-pandemic period (2018), with an increase of 34.3% compared to the year 2020. This conclusion was possible since there was also a decline of 43.5% of cases, when comparing the years 2019 and 2020. Keywords: mental disorders, teleworking, COVID-19.