Background: Coronavirus disease (COVID-19) is a global health issue that keeps testing academic efforts to cease it. Many factors are involved in progression to severe disease including metabolic and inflammatory disorders. The aim of this study is to analyze the factors associated with mortality in those admitted for COVID-19 in the Intensive Care Unit (ICU) of a hospital in Espirito Santo, Brazil. Methods: This is a retrospective, cross-sectional study, with data collection from medical records. The primary outcome studied is mortality, categorized by length of stay in the ICU. A total of 163 patients were included in this study. The data of these patients where then separated in two groups, first with 93 discharges and second with 64 deaths. The parametric Student’s T-test and the nonparametric Mann–Whitney U test for continuous data and the χ2 and Fisher’s exact test for categorical data were used to compare the variables between both groups. Variables with a p-value < 0.05 (in the bivariate analysis) were submitted to the Cox Survival Hazard multivariate survival model. Results: Bivariate analysis identified as factors on admission associated with mortality: age > 60 years, high blood pressure, diabetes mellitus, heart disease, cerebrovascular disease thrombocytopenia, lactate dehydrogenase elevation, D-dimer elevation and use of supplemental oxygen. Complications while on ICU associated with higher mortality are: mechanical ventilation, mechanical ventilation> 14 days, acute renal failure, bacterial pneumonia, post COVID-19 acute arrhythmia, bloodstream infection, acute renal injury and anemia. To exclude possible interference, a multifactorial analysis was applied with the Cox Survival Hazard proportional risk model, showing that mechanical ventilation (OR: 17.254, 95%CI 4.35-68.43, p <0.0001) and anemia (OR: 2.17, 95%CI 1.15-4.09, p<0.016) are independent variables related to mortality. Conclusion: This study identified that anemia on admission and the need to provide mechanical ventilation during ICU stay are independent factors for predicting mortality.