To assess the diagnostic accuracy of the clinical pulmonary infection score in the diagnosis of ventilator-associated pneumonia in mechanically ventilated patients. We searched PubMed and the Cochrane database, and included only studies that compared clinical pulmonary infection score with quantitative microbiological analysis of samples for diagnosing ventilator-associated pneumonia. We constructed 2-by-2 tables of diagnostic accuracy from each article, and meta-analyzed the results by pooling estimates of sensitivity, specificity, likelihood ratio for positive index test, likelihood ratio for negative index test, diagnostic odds ratio, and 95% confidence intervals. Thirteen studies met the inclusion criteria. The pooled estimates for sensitivity and specificity for clinical pulmonary infection score were 65% (95% CI 61-69%) and 64% (95% CI 60-67%), respectively. The combined diagnostic odds ratio was 4.85 (95% CI 2.42-9.71) and the area under the curve was 0.748 (95% CI 0.65-0.85). The diagnostic performance of the clinical pulmonary infection score for ventilator-associated pneumonia is moderate. However, the clinical pulmonary infection score is simple and easy to perform, and may still be useful in diagnosing ventilator-associated pneumonia.