The objective of this study was to analyze the effect of the COVID-19 pandemic on suicide rates among Brazilian residents, stratified by sex. This study evaluated the behavior of monthly suicide rates based on an interrupted time series analysis of the months preceding (from January 2017 to February 2020) and following (from March 2020 to December 2022) the first diagnosed case of Covid-19 in Brazil. We used an interrupted time series model (quasi-Poisson), accounting for the presence of serial autocorrelation in the residuals and seasonality.Among men, we identified an abrupt decrease (RR<1, p<0.05) in monthly suicide rates at the onset of the pandemic, followed by a progressive increase (RR>1, p<0.05). An exception to this trend occurred in the Northeast region and among elderly men, where there was an abrupt increase in suicide rates at the start of the pandemic. For women, a reduction in monthly suicide rates was observed during the early stages of the pandemic only in the Central-West and Northeast regions, as well as in the 20-39 age group.The pandemic's effect was not uniform across Brazilian men and women, according to stratification variables; however, we observed a progressive upward trend over the course of the pandemic.