ObjectiveTo evaluate the clinical significance of procalcitonin (PCT) for the diagnosis and prognosis of infections in patients.MethodsPCT and blood culture data of patients in a hospital from September 2009 to December 2010 were analyzed retrospectively.ResultsAmong 570 detected samples, the positive rate of PCT and blood culture was 46.49% (265/570) and 30.18% (172/570) respectively; when PCT=0.50ng/mL was used as the cutoff value of diagnosis, the sensitivity and specificity of PCT was 90.53%（516/570）and 64.74%（369/570） respectively, the positive and negative predictive value of PCT was 44.53%（118/265）and 82.30%(251/305) respectively.ConclusionQuantitative PCT has important guiding significance for the early diagnosis and prognosis evaluation of infections in patients, it can provide evidence for clinical decisionmaking by continuously monitoring infections in patients.