Introduction Little is known about how sheltering in place to contain the spread of COVID-19 over extended periods affects individuals’ psychological well-being. This study’s objective was to analyze the factors associated with MSM’s (men who have sex with men) low psychological well-being in the COVID-19 pandemic context. Method This cross-sectional study was conducted online across Brazil (26 states and federal district) in April and May 2020. The participants were recruited using snowball sampling and Facebook posts. Data were collected using social media and MSM dating apps. We estimated the prevalence, crude prevalence ratio (PR), and the respective confidence intervals (CI95%). Results The prevalence of low psychological well-being found in the sample was 7.9%. Associated factors were belonging to the youngest group (PR 2.76; CI95% 1.90–4.01), having polyamorous relationships (PR 2.78; CI95% 1.51–5.11), not complying with social isolation measures (PR 6.27; CI95% 4.42–8.87), not using the social media to find partners (PR 1.63; CI95% 1.06–2.53), having multiple sexual partners (PR 1.80; CI95% 1.04–3.11), having reduced the number of partners (PR 2.67; CI95% 1.44–4.95), and group sex (PR 1.82; CI95% 1.23–2.69) Conclusion The well-being of MSM living in Brazil was negatively affected during the social distancing measures intended to control the spread of COVID-19. The variables that contributed the most to this outcome include social isolation, relationships established with partners, and sexual behavior. Policy Implications Planning and implementing public policies and actions to promote psychological well-being are needed to improve MSM’s resilience by adopting safe strategies and behavior.

Introduction: Little is known about how sheltering in place to contain the spread of COVID-19 over extended periods affects individuals' psychological well-being. This study's objective was to analyze the factors associated with MSM's low psychological well-being in the COVID-19 pandemic context. Method: This cross-sectional study was conducted online in the entire Brazilian territory (26 states and federal district) in April and May 2020. The participants were recruited using an adapted version of Respondent-Driven Sampling (RDS). Data were collected using social media and MSM dating apps. We estimated the prevalence, crude prevalence ratio (PR), and respective confidence intervals (CI95%). Results: Only 44.4% of the sample presented high levels of well-being. Low psychological well-being appeared associated with the youngest age group (PR: 2.76; CI95%: 1.90-4.01), polyamorous relationships (PR: 2.78; CI95%: 1.51-5.11), not complying with social isolation measures (PR: 6.27; CI95%: 4.42-8.87), not using the social media to find partners (PR: 1.63; CI95%: 1.06-2.53), having multiple sexual partners (PR: 1.80; CI95%: 1.04-3.11), having reduced the number of partners (PR: 2.67; CI95%: 1.44-4.95), and group sex (PR: 1.82; CI95%: 1.23-2.69) Conclusion: The well-being of MSM living in Brazil was negatively affected during the social distancing measures intended to control the spread of COVID-19. Policy Implications: Planning and implementing public policies and actions to promote psychological well-being are needed to improve MSM's resilience through the adoption of safe strategies and behavior.