INTRODUCTION: Sepsis is a disease that is still associated with high mortality, in which timely interventions are related to better results. OBJECTIVE: To determine if there is a difference in in-hospital mortality, fluid balances, norepinephrine initiation and recovery time of blood pressure, when comparing the resuscitation of the patient who is admitted to the emergency room in septic shock by applying the ultrasound protocol (USER) versus the standard of care. PATIENTS AND METHODS: This is a prospective, cohort study conducted in the emergency room of a highly complex hospital of patients with septic shock. RESULTS: 83 patients recruited in total. The groups were comparable in demographics, mean baseline blood pressure, disease severity given by the SOFA value, and arterial lactate. A statistically significant difference was documented in the fluid balances at 4 hours, median 1325mL (IQR:451-2455mL) in Group C versus 900mL (IQR:440-1292) in Group U (p=0.048) and at 6 hours, median 1658mL (IQR:610-2925mL) versus 1107mL (IQR:600-1500mL), p=0.026, as well as in the total fluid balance of hospital stay, median 14,564mL (IQR:8660-18,705mL) versus 8660mL (IQR:5309-16,974mL), p=0.049. On the other hand, in the USER Group, the mean blood pressure ≥ 65mmHg was achieved in 97.4% of the patients 4 hours after the start of the protocol versus 50% in Group C (p=<0.001). Mortality with the use of the protocol compared with conventional therapy was (56.4% vs 61.36%, p=0.647). CONCLUSION: The use of the USER protocol in patients with septic shock in the emergency room showed lower fluid balances at 4 and 6 hours, and of the total hospital stay, as well as earlier initiation of norepinephrine and statistically significant faster improvement in blood pressure. Although a statistically significant difference was not found in the days of ICU stay, hospitalization and in-hospital mortality, a trend was observed in the reduction of these parameters.