Background Timely recognition of sepsis in emergency department (ED) is challenging. We evaluated the impact of implementing the biomarker monocyte distribution width (MDW) at bedside, on the time to anti-infective administration. Methods : We conducted a before-and-after cohort study in the ED of an academic hospital in Paris, to compare sepsis patients care and outcomes, before and after the implementation of point of care (POC) MDW measurement in the ED. During post-implementation period (period-2), MDW was measured with complete blood count by ED nurses with results given in 2 min: if above 21.5 units, ED physicians were asked to consider sepsis and to start an antiinfectious as soon as possible. Primary endpoint was time to anti-infectious administration (TTA) from ED arrival, and secondary endpoints were TTA from sepsis onset (TTAS), length of stay, mortality, and hospitalization rates. Results : In total, 255 patients (period-1) and 180 patients (period-2) with sepsis were included. The TTA was 5.4 h (3.5-7.7) period-1 and 4.9 h (IQR 2.5-7.1) in period-2 (p = 0.06). MDW implementation significantly reduced the median TTAS from to 3.7 h (IQR 1.5-5.8) in period-1, to 2.2 h (IQR 0.5-4.5) in period-2 (p < 0.001). Mortality rates remained similar between the two periods (18% vs. 16% respectively, p = 0.4), as did hospitalization rates (93% vs. 91%, p = 0.4) and ED length of stay (7.2 h (5.3-9.8) vs 7.0 (5.4-9.4), p = 0.7). Conclusion : Implementing POC MDW measurement in the ED protocols enhances the timeliness of anti-infective administration from sepsis onset, meeting current sepsis management guidelines.