Objective To evaluate the diagnostic value of soluble triggering receptor expressed on myeloid cells-1 ( sTREM-1 ) in endotracheal aspirate and plasma of patients with ventilator-associated pneumonia ( VAP) . Methods The consentration of sTREM-1 in plasma and endotracheal aspirate, and serum high-sensitivity C-reactive protein ( hs-CRP) were measured by enzyme-linked immunosorbent assay ( ELISA) in 68 patients with VAP ( VAP group) , 50 patients underwent ventilation without VAP ( non-VAP group) , and 50 healthy individuals ( control group) . The sensitivity and specificity of each parameter were calculated. Results In the patients with VAP, sTREM-1 in plasma and endotracheal aspirate before treatment were significantly higher than that in the non-VAP group [ ( 143.62 ±46.82) pg/mL vs. ( 68.56 ±16.24) pg/mL, ( 352.86 ±92.57) pg/mL vs. ( 126.21 ±42.28) pg/mL, Plt;0.05] ; sTREM-1 in plasma and endotracheal aspirate on the 3rd and the 7th day during treatment were significantly decreased ( Plt;0. 05) . By ROC analysis, the cut-off value of sTREM-1 in endotracheal aspirate were 193.64 pg/mL, with sensitivity and specificity of 93.84% and 89.51% respectively. The areas under ROC curve of sTREM-1 in endotracheal aspirate were 0.912. Clinical diagnostic value of sTREM-1 in endotracheal aspirate was better than plasma sTREM-1 and serum hs-CRP ( areas under ROC curve were 0. 768 and 0. 704 respectively) . Conclusions sTREM-1 may be helpful for evaluating the therapeutic effect in patients with VAP. The diagnostic value of sTREM-1 in endotracheal aspirate may be superior to plasma sTREM-1 and serum hs-CRP.