Procalcitonin is a promising biomarker for antibiotic therapy because its levels rise and fall quickly with bacterial infections. A multidatabase literature search was reviewed with 3 primary prospective randomized control trials used in further analysis. The results indicated that a procalcitonin-guided antibiotic protocol reduces the number of days a patient has to take antibiotics while having no effect on mortality when compared with control groups. Short-term studies did not show a difference in the intensive care unit length of stay, infection relapse rate, superinfection rate, or multidrug-resistant bacteria rate between the procalcitonin-protocol and control group. Because procalcitonin-guided antibiotic therapy has been shown to reduce the duration of treatment with antibiotics in critically ill patients without worsening the mortality rate or other outcomes, the implementation of a procalcitonin-guided antibiotic therapy should be considered for patients with proven or highly suspected bacterial infections in the intensive care unit.