Introduction:A comprehensive cytometry assessment in the critical ill patient shows modifications in cell lines that estimate severity and mortality in sepsis. The objective of this study is to determine the utility of different cytometric parameters and indices as predictors of mortality in septic patients. Materials and Methods: Retrospective cohort study of adults with sepsis (SEPSIS Criteria 3) hospitalized in an Intensive Unit Care (Quito, Ecuador). Patients with neoplasms or immunodeficiency states were excluded. Different cytometric parameters have been assessed and logistic regression models were used to stablish the predictive range of mortality for each parameter and areas under the curve (AUC) for sensitivity analysis. Results: Over 159 patients, the mortality was 25%. In non-survivors, the median of the APACHE II was 25.20 points, and the median of the SOFA was 11.18, 10.44, 10.15 points at the time of admission, 48, and 72 hours respectively. About the sensitivity analysis for mortality, the cut-off point of EDW was 14.5% (AUC 0.708), and it presented an adjusted OR of 5.25 (95%CI: 1.64-16.76, p: 0.005). The cut-off point of MPV was 8.45 fL (AUC 0.666), and it had an adjusted OR of 5.28 (95%CI: 1.72-16.21, p 0.004). Conclusions: EDW and MPV are independent predictors of mortality, and they must be used with scales or biomarkers to optimize the management and therapy of patients with sepsis. They would be an alternative in centers where only blood cytometry is available as an analytical test.