We assessed whether acid-fast bacilli (AFB) investigation in bronchial lavage (BL) contributes to diagnosis in patients with gastric lavage smear negative and radiologically suggestive of pulmonary tuberculosis. Eighty-three patients were recruited for the study, five cases were excluded due to diagnosis of inactive disease or non-tuberculosis disease. The remaining 78 patients were evaluated. All patients were unable to expectorate sputum and their gastric lavages were negative for AFB. BL was performed for the detection of Mycobacterium tuberculosis in all patients. Bronchial lavage smear were positive in 15.4%(12 patients). BL culture positivity was 58.3%(42 patients) and gastric lavage culture positivity was 33.3%(26 patients). Eighteen cases had both gastric lavage and BL culture positivity. BL culture was positive in 24 cases who had gastric lavage culture negativity. We suggest that in cases who do not produce sputum and whose gastric lavage smears are negative; BL should be performed for diagnosis of pulmonary tuberculosis.