Over the last 25 years, procalcitonin (PCT) has increasingly been utilized to identify patients with bacterial sepsis. PCT is a 14.5 kDa protein derived from the CALC-1 gene and belongs to the family of hormones. Released from liver, fat, muscle, and kidney parenchymal cells, PCT has been determined to be quite specific to bacterial infections. Although its physiology has not been fully elucidated, its kinetics has proven to be a valuable asset to clinical decision making when compared to other markers of inflammation such as C-reactive protein and the white cell count. PCT has also been used to determine when to commence and when to cease antibiotic therapy across a host of conditions such as sepsis, pneumonia, and burns in both adult and pediatric populations. PCT's prognostic value has also been recognized along with its non-infectious indications like appendicitis and burns. Relatively newer biomarkers such IL-6, LBP, and presepsin are also being identified in the field of critical care and could provide effective strategies towards the early diagnosis of serious bacterial infections.