Abstract: Objective To evaluate thediagnostic value of procalcitonin (PCT) indiagnosis of periprosthetic joint infection (PJI). Methods Eighty patients in ourdepartment who were suspected with PJI after total joint arthroplasty were enrolled in our study from September 2014 to June 2015. Patients weredivided into PJI group and non-infection group according to MSIS guideline, and every patient had undergone serum test including PCT, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6) and white blood cell (WBC). Thediagnostic value of PCT was evaluated. Results Of the 80 patients, 38 cases were in PJI group (17 men and 21 women) with average age of (62.8±12.9) years (ranging from 31 to 80), and 42 cases in non-infection group (17 men and 25 women) with average age of (53.3±16.0) years (ranging from 21 to 85). There were significantdifferences in WBC, ESR, CRP and IL-6 between two groups (P=0.000). However, there were nodifferences in PCT between two groups (P=0.397). The area under ROC curve of IL-6, CRP, ESR and WBC were 0.915 (P=0.000), 0.911 (P=0.000), 0.910 (P=0.000), 0.771 (P=0.000), respectively. While the area under ROC curve of PCT was 0.509 (P=0.893). Conclusion According to our study, PCT are not recommended in thediagnosis of PJI.