Background and Objectives: Early diagnosis of tuberculosis (TB) is important in public heath, especially in an intermediate TB burden country. However, we are often difficulty in discriminating pulmonary TB from bacterial community acquired pneu-monia (CAP) based on histology, physical examination, and radiological findings. Therefore, requirement for a rapid and readily available test to discriminate pulmonary TB from CAP in increasing. We investigated the role of the neutrophil-lymphocyte count ratio (NLR), a convenient marker of inflammation, to discriminate pulmonary TB from bacterial CAP. Methods: We retrospectively analyzed clinical and laboratory characteristics of 206 patients who were suspected of having pulmonary TB or bacterial CAP from 2009 to February 2011. The diagnostic ability of NLR in differential diagnosis was eval-uated and compared with that of C-reactive protein, WBC count, neutrophil count and lymphocyte count. Results: A NLR value ＜7 was the optimal cut-off value to discriminate patients with pulmonary TB from patients with bacte-rial CAP (sensitiviy 91.1%, specificity 81.9%, positive predictive value 85.7%, negative predictive value 88.5%). The area under the curve for NLR (0.95, 95% CI, 0.91-0.98) was significantly greater than that of C-reactive protein (0.83, 95% CI 0.76-0.88; p=0.0003), WBC count (0.86, 95% CI 0.80-0.91; p=0.0052), lymphocyte count (0.72, 95% CI, p＜0.0001) and neutrophil count (0.89, 95% CI 0.84-0.93; p=0.0745). Conclusion: NLR was useful laboratory marker to discriminate pulmonary TB from patients with bacterial CAP.