Objective: To identify clinical indicators and nursing diagnoses with the highest risk of mortality in critically ill patients with COVID-19. Method: Retrospective cohort with the population of adults and elderly people with COVID-19 from an Intensive Care Unit. Categorical variables were described using absolute and relative frequencies and risk factors for mortality using Cox regression, with a confidence interval of 95%. Results: The main clinical indicators of COVID-19 patients were dyspnea, fever, fatigue, cough, among others, and the Nursing Diagnoses at higher risk of mortality were Ineffective protection, Ineffective tissue perfusion, Contamination, Ineffective Breathing Pattern, Impaired spontaneous ventilation, Acute confusion, Frailty syndrome, Obesity, and Decreased cardiac output. It is worth mentioning that there was little information about the diagnoses of Domains 9, 10, and 12. Conclusion: This research infers the need to monitor the clinical indicators dyspnea, fever, fatigue, cough, among others, and the Nursing Diagnoses with the highest risk of mortality Ineffective protection, Ineffective tissue perfusion, Contamination, Ineffective Breathing Pattern, Impaired spontaneous ventilation in critically ill patients.