Due to the high rates of transmission and deaths due to COVID-19, understanding the factors associated with its occurrence, as well as monitoring and implementing control measures should be priority actions in health surveillance, highlighting the use of epidemiological surveillance information systems as an important ally. Thus, the objectives of this study were to calculate the mortality rate of hospitalized patients with severe acute respiratory syndrome due to COVID-19 and to identify factors associated with death, in the period corresponding to epidemiological weeks 01 to 53 of the year 2020. This was a longitudinal study, using the national influenza epidemiological surveillance information system database, routinely collected by healthcare services. The sociodemographic and clinical characteristics of 563,051 hospitalized patients with severe acute respiratory syndrome due to COVID-19 in the five regions of Brazil were analyzed. Cox regression was performed to assess factors associated with patient death during hospitalization. The national lethality rate was 35.7%, and the highest rates of lethality occurred in the Northeast (44.3%) and North (41.2%) regions. During the hospital stay, death was associated with older age (Hazard Ratio-HR = 1.026; p<0.001); male sex (HR = 1.052; p<0.001); living in the North (HR = 1.429; p<0.001), Northeast (HR = 1.271; p<0.001) or Southeast regions of Brazil (HR = 1.040; p<0.001), presenting any risk factor (HR = 1.129; p< 0.001), the use of invasive (HR = 2.865; p<0.001) or noninvasive (HR = 1.401; p<0.001) mechanical ventilation devices. A high case lethality rate was evidenced in patients with severe acute respiratory syndrome due to COVID-19, however, deaths were not evenly distributed across the country's regions, being heavily concentrated in the Northeast and North regions. Older male patients living in the North, Northeast, or Southeast regions of Brazil, who presented any risk factor and were submitted to the use of invasive or noninvasive mechanical ventilation devices, presented a higher risk of evolving to death.