Background: Because most studies of tuberculous pleural effusion (TPE) focused on the pleural space, little information regarding lung parenchyma is available. We hypothesized that TPE patients without pulmonary tuberculosis (TB) would have pulmonary immunological changes. Aim: Investigate the composition of cells in the bronchoalveolar lavage (BAL) in TPE patients without pulmonary TB and to compare BAL composition of the same and contra lateral side of the TPE. Methods: Newly diagnosed untreated patients with TPE were enrolled in this study. TPE was confirmed in all cases by pleural biopsy. Patients with any evidence of pulmonary TB were excluded. BAL was performed at the same (Group 1:G1) and the contra lateral side (Group 2:G2) of TPE. All patients were consenting for participation in the study. Results: During the study period, 19 patients were enrolled (10 female and 9 male). Mean age was 40 ± 19 years. Clinical manifestations were dominated by chest pain and fever. Pleural effusion was unilateral in all cases (right-side: 14 cases, left-side: 5 cases). Tuberculin skin tests were positive in 8 patients and peripheral blood lymphopenia was found in 10 cases. BAL fluid formula was abnormal in 17 cases (G1) versus 10 cases G2 (p 0.05). There were significant immune responses in the same side of TPE patients without pulmonary tuberculosis. Conclusion: These results suggest that TPE may induce a significant immune response in lung parenchyma especially in adjacent tissue.