Objective Determine whether the levels of glycated hemoglobin (HbA1c) measured on admission to the intensive care unit (ICU) are associated with mortality in patients with severe SARS-CoV-2 pneumonia with invasive mechanical ventilation. Design Cohort study, retrospective, observational. A single center. Place ICU of a second-level care hospital. Patients Severe SARS-CoV-2 pneumonia confirmed with IMV since admission to the ICU. Interventions none. Results A total of 56 patients with severe pneumonia, confirmed with SARS-CoV-2, all with IMV. The group with HbA1c = 6.5% included 24 (42.86%) patients and the mortality rate in ICU was 43.8% and 70.8%, respectively, with p = 0.04. Predictors of mortality at 28 days in ICU were DHL >500 U/L, OR 3.65 (95% CI 1.18-11.29), HbA1c >= 6.5%, OR 3.12 (95% CI 1.01-9.6), SAH, OR 3.12 (95% CI 1.01-9.5), use of vasopressor, OR 0.2 (95% CI 0.05-0.73), diabetes was not statistically significant. Conclusion The 28-day probability of survival in patients with severe SARS-CoV-2 pneumonia with IMV in the ICU is lower when the HbA1c level is >= 6.5% on admission.