Objective To investigate the values of pneumonia severity index ( PSI) , CURB-65,plasma procalcitonin ( PCT) , C-reactive protein ( CRP) measurements for evaluation the severity of healthcare-associated pneumonia ( HCAP) .Methods A retrospective observational study was conducted on 92 hospitalized patients with HCAP admitted between June 2010 and December 2011. They were divided into different groups according to different severity assessment criteria. The variance and correlation of PCT,CRP,WBC and percent of neutrophil ( Neu% ) levels were compared among different groups. ROC curvewas established to analyze PSI, CURB-65, PCT and CRP levels for predicting the motality of HCAP patients.Results In the severe HCAP group, PSI and CURB-65 scoring and serum PCT, CRP, WBC, Neu% levels were significantly higher than those in the non-severe HCAP group( P lt; 0. 05) . In the high-risk HCAP group, PCT, CRP, WBC and Neu% levels were significantly higher than those in the low-risk HCAP group according to the PSI and CURB-65 scoring criteria( P lt;0. 05) .WBC and Neu% levels were also significantly higher than those in the moderate-risk group. PSI and CURB-65 scoring were positively correlated with PCT and CRP levels. PSI scoring gt;120 points or CURB-65 scoring gt;2 points on admission were predictors of mortality. Conclusions PSI and CURB-65 scoring are correlated with severity of HCAP. Combining serum PCT and CRP levels can improve the predictive accuracy of the severity of HCAP.