Objective To explore the value of procalcitonin(PCT)in diagnosis of early-onset stroke-associ-ated pneumonia and prognosis of patients with acute stroke.Methods 37 patients with acute stroke admitted to inten-sive care unit were enrolled in this study.The clinical data of patients were recorded and the maximum temperature, the serum levels of WBC,PCT and CRP were measured at 1,2,and 3 days respectively after admission.The follow up period was 28 days.Patients were divided into early-onset stroke-associated pneumonia (EOP)group and NEOP group by related examination results.According to the mean of serum PCT concentration,those patients were divided into high-PCT level(≥0.5μg/L)and low-PCT level group(<0.5μg/L).The difference of PCT level between EOP group and NEOP group was analyzed.SPSS13.0.Kaplan-Meier curves were used to analyze the survival at 28 days between the high and low PCT level group,and multivariate analysis of COX regression model was used to find the prognosis factors for survival.Results Statistically significant differences were observed for the comparison of PCT values at three days of admission between EOP and NEOP group [First day:(2.18 ±0.76 )μg/L vs (1.14 ± 0.64)μg/L.Second day:(2.10 ±0.79)μg/L vs (1.19 ±0.64)μg/L.Third day:(2.02 ±0.78)μg/L vs (1.17 ± 0.55)μg/L](t =4.250,3.625,3.573,all P <0.05).Kaplan-Meier survival analysis showed that there was signifi-cant difference in 28-day survival between the high and low PCT level group(mean survival time 21.8 vs 26.2 days,χ2 =4.659,P =0.031 ).Multivariate COX regression analysis revealed that PCT was independent risk factor of 28-day mortality(Wald =4.084,P =0.043).Conclusion The detection of PCT can be an effective parameter for diagnosis of EOP.High PCT levels indicate poor prognosis in patients with acute stroke.