The COVID-19 pandemic represented a challenge in medical care. A tool would be very useful to establish the prognosis of in-hospital death that is reliable and can be applied to the Mexican population entitled to the IMSS.To propose a prognostic scale to stratify patients with viral pneumonia COVID-19 in the emergency services.A nested case-control study was conducted in a cohort of patients who were consecutively admitted to the emergency department with viral pneumonia COVID-19. The cases were those patients who died, and the controls were those who were discharged due to health improvement. An association analysis was performed between the variables with significant differences between groups. Subsequently, the association was adjusted using a multivariate logistic regression model, from which the prognostic scale was developed.A total of 70 subjects with COVID-19 were included, 34 cases and 36 controls. Chronic diseases, smoking, severe pulmonary involvement diagnosed by tomography, leukocytosis, and pulse oximetry less than 80% with were associated with in-hospital mortality; Odds Ratio (OR) of >1.1. Vaccination was a protective factor (OR = 0.04, CI95%: 0.01-0.16). A score greater than 3 points on the prognostic scale predicts in-hospital mortality with a specificity of 0.86 and a sensitivity of 0.73.The proposed prognostic scale can be a useful tool in the classification of patients with COVID-19 viral pneumonia in the emergency room services of secondary care level Hospitals.Licencia CC 4.0 (BY-NC-ND) © 2023 Revista Médica del Instituto Mexicano del Seguro Social.