OBJECTIVE: To investigate and evaluate the diagnostic and predictive value of procalcitonin (PCT) for ICU fever patients with bloodstream infections(BSI). METHODS: Medical records of 233 ICU fever patients in our hospital during Mar. 2012 to Dec. 2014 were analyzed retrospectively. Serum levels of PCT and CRP were compared among patients with different blood culture results, pathogen types and species of bacterial infection. The diagnostic and predictive value of PCT and CRP for BSI were evaluated and compared by using ROC curves. RESULTS: Among 233 fever patients, there were 74 cases of positive blood culture with positive rate of 31.76%. The serum levels of PCR and CRP in patients with positive blood culture were higher than in those with negative blood culture and contamination, with statistical significance (P<0.001). There was no statistical significance in serum levels of PCR and CRP between negative blood culture group and contamination group (P>0.05). Among 74 patients with positive blood culture, there were 45 cases of gram-negative bacterial infection, accounting for 60.81%; 18 cases of gram-positive bacterial infection, accounting for 24.32%; 11 cases of fungi infection, accounting for 14.86%. Serum level of PCT in patients with gram-negative bacterial infection was higher than in those with gram-positive bacterial infection and fungi infection, and serum level of PCT in patients with gram-positive bacterial infection was higher than in those with fungi infection, with statistical significance (P<0.05). There was no statistical significance in serum level of CRP among patients with 3 kinds of bacterial infection (P>0.05). Main bacteria of infection in fever patients included Acinetobacter, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae; there was statistical significance in serum level of PCT among various bacterial infection (P<0.05); there was no statistical significance in serum level of CRP (P>0.05). ROC curve analysis demonstrated there was statistical significance in differentiation of distinguishing positive and negative blood culture by PCT and CRP (P<0.001); AUROC were 0.789 [95%CI (0.732, 0.845)] and 0.629 [95%CI (0.568, 0.690)]; cutoff value were 1.2 ng/ml and 81.4 mg/L. There was statistical significance in the differentiation of distinguishing positive blood culture and contamination by PCT and CRP (P<0.001); AUROC were 0.805 [95%CI(0.711, 0.899)] and 0.673 [95%CI (0.540, 0.805)]; cutoff value were 0.5 ng/ml and 73.4 mg/L. CONCLUSIONS: PCT may be a useful tool for the diagnosis of BSI and the judgment of blood culture results in ICU fever patients, and its predictive function was better than CRP. Serum level monitoring of PCT can guide the early empirical anti-infective therapy of BSI.