Procalcitonin is used as a marker for sepsis but there is little known about the correlation of the procalcitonin elevation with the causative organism in sepsis. All patients aged 18 to 80 years who were admitted to the surgery service from June 2010 to May 2012 and who had a procalcitonin drawn were evaluated. Culture data were reviewed to determine the causative organism. Infections analyzed included pneumonia, urinary tract infection (UTI), bloodstream infection, and Clostridium difficile. Other parameters assessed included reason for admission, body mass index, pressor use, antibiotic duration, and disposition. Two hundred thirty-two patient records were reviewed. Patients without a known infection/source of sepsis had a mean procalcitonin of 3.95. Those with pneumonia had a procalcitonin of 20.59 (P = 0.03). Those with a UTI had a mean procalcitonin of 66.84 (P = 0.0005). Patients with a bloodstream infection had a mean procalcitonin of 33.30 (P = 0.003). Those with C. difficile had a procalcitonin of 47.20 (P = 0.004). When broken down by causative organisms, those with Gram-positive sepsis had a procalcitonin of 23.10 (P = 0.02) compared with those with Gram-negative sepsis at 32.75 (P = 0.02). Those with fungal infections had a procalcitonin of 42.90 (P = 0.001). These data suggest that procalcitonin elevation can help guide treatment by indicating likely causative organism and infection type. These data may provide a good marker for initiation of antifungal therapy.