Objective To investigate the influence of pulmonary infection on noninvasive ventilation ( NIV) therapy in hypercapnic acute respiratory failure ( ARF) due to acute exacerbation of chronic obstructive pulmonary disease ( AECOPD) , and evaluate the predictive value of simplified version of clinical pulmonary infection score ( CPIS) for the efficacy of NIV therapy in ARF patients with AECOPD. Methods Eighty-four patients with ARF due to AECOPD were treated by NIV, and were divided into a successful group and an unsuccessful group by the therapeutic effect of NIV. The CPIS and simplified version of CPIS between two groups was compared. The predictive value of simplified version of CPIS for the efficacy of NIV wasevaluated using ROC curve analysis. Results The CPIS and the simplified version of CPIS of the successful treatment group ( 4. 0 ±2. 8, 3. 2 ±2. 4) were lower than those of the unsuccessful group ( 8. 0 ±2. 1, 7. 2 ±1. 8) significantly ( P =0. 006, 0. 007) . The area under ROC curve ( AUC) of CPIS and simplified version of CPIS were 0. 884 and 0. 914 respectively, the cut oint of CPIS and simplified version of CPIS were 6 ( sensitivity of 78. 0% , specificity of 91. 2% ) and 5 ( sensitivity of 80. 0% , specificity of 91. 2% ) respectively. Conclusions The level of pulmonary infection is an important influencing factor on the therapeutic effect of NIV in patients with ARF due to AECOPD. Simplified version of CPIS is a helpful predictor for the effect of NIV on ARF of AECOPD.