Due to significant mortality and morbidity which may be reduced by prompts treatment, there is great interest in determining an ideal biomarker for the diagnosis of sepsis upon presentation to the Emergency Department. The most specific test is a positive blood culture, but its sensitivity is very low, and the results are usually available 2 days after sampling. For this reason, research is conducted into serum biomarkers with greater sensitivity for which results can be available within hours of presentation. High initial procalcitonin levels are a sensitive marker of bacterial infection, and the degree of procalcitonin elevation may determine which patients are at greater risk for adverse outcomes (mortality or ICU admission). The purpose of this narrative review is to evaluate the utility of procalcitonin as a diagnostic marker of sepsis in the emergency department and the use of procalcitonin-guided management algorithms.