Background: Anatomic localizations of septic foci and the relationship between these localizations and procalcitonin (PCT) in the clinical picture of sepsis/septic shock induced by these foci is not a sufficiently investigated topic. We aimed to determine the relationship between sepsis foci and procalcitonin values in intensive care patients. Methods: Data of the patients who were admitted in the intensive care unit and diagnosed with sepsis/ septic shock between 2016 and 2018 were analyzed retrospectively. The patients were grouped based on the localization of the infectious foci as respiratory system, urinary system, blood-catheter, soft tissue and abdominal. Additionally, the patients were grouped also based on number of foci and growing microorganisms. Subsequently, the relationship between septic foci and routine laboratory parameters, primarily PCT, was investigated statistically. Results: Totally 630 infection periods were analyzed in 424 patients who were diagnosed with sepsis/septic shock in the intensive care unit. Incidence of sepsis/septic shock was 36.5% while mortality rate was 65.6% in these patients. A higher mortality rate was encountered in the infections with two or multiple foci (p <0.001). Multiple-focal infections revealed higher PCT values than the single focal infections (p = 0.021). A higher mortality rate was detected in the patients with microbial growth in the respiratory infections than those with urinary and abdominal infections (p <0.001). The patients with microbial growth reported from blood and abdominal cultures revealed higher PCT levels than other patients groups (p <0.001). Conclusions: Higher procalcitonin levels are related to presence of multiple foci of infection and, as well, to higher mortality rates.