The overuse of antibiotics in surgical patients contributes to antimicrobial resistance, Clostridioides difficile infection and unnecessary healthcare costs. Procalcitonin (PCT) is a biomarker of bacterial infection and sepsis and has been used to guide antibiotic initiation and duration. However, its role in postoperative surgical patients is unclear due to concerns regarding specificity and postoperative inflammatory kinetics. This review explores the evidence for PCT-guided antibiotic therapy in surgical patients, focusing on postoperative infection management and antimicrobial stewardship. A narrative review of published literature was conducted, including studies assessing PCT-guided protocols in postoperative infections, intra-abdominal sepsis, and critically ill surgical patients. Evidence suggests that PCT-guided protocols can safely reduce antibiotic duration without increasing morbidity or mortality. Serial PCT measurements, interpreted alongside clinical assessment and microbiology results, provide the greatest benefit. Implementation studies demonstrate improved guideline adherence, reduced antibiotic exposure, and cost savings in surgical units adopting PCT-based algorithms. PCT is a promising adjunct for guiding antibiotic therapy in surgical patients, supporting more targeted prescribing and improved antimicrobial stewardship. Surgeons should interpret PCT trends within the broader clinical context rather than relying on isolated values. Further research is required to establish procedure-specific thresholds and implementation frameworks to optimise PCT use in general surgery. References: 1. Schroeder S, Hochreiter M, Koehler T, et al. Procalcitonin (PCT)-guided algorithm reduces length of antibiotic treatment in surgical intensive care patients with severe sepsis: results of a prospective randomized study. Langenbecks Arch Surg. 2009;394(2):221–226. doi:10.1007/s00423-008-0432-1