A retrospective study included 128 intensive care unit (ICU) patients with sepsis, divided by qSOFA score < 2 and ≥ 2. Patients with qSOFA ≥ 2 had significantly higher ICU and 28-day mortality as well as consistently higher lactate and procalcitonin (PCT) levels on admission, at 24 and 72 hours. Lactate, PCT and qSOFA were independent predictors of mortality and disease severity. The combination of these three markers achieved better predictive accuracy with an AUC of 0.79 for ICU mortality and 0.81 for 28-day mortality, outperforming qSOFA alone or in combination with only one biomarker. Dynamic monitoring of lactate and PCT levels during the first 72 hours significantly improves the prognostic assessment of patients with sepsis. The results support the use of a combined qSOFA, lactate, and PCT model for better risk stratification and early identification of patients at higher risk of ICU death.