OBJECTIVE To evaluate the role of transbronchial needle aspiraion (TBNA) in the diagnosis of bronchogenic carcinoma with enlarged mediastinal and/or hilar lymph node. METHODS Patients with mediastinal and/or hilar lymphoadenopathy proven by CT scan were eligible for TBNA as reported by WANG. All specimen was directly and instantly smeared for cytological examination. RESULTS From June 2004 to May 2006, 77 such patients were examined: including 38 lung cancers, 35 lung benign diseases and 4 without definite diagnosis. All TBNA procedures were successfully carried out in 222/225 ( 98.7%). Positive TBNA rate was 81.6% (31/38) in patients who had been proven to suffer from bronchogenic carcinoma. The diagnosis of lung cancer was confirmed via TBNA only in 9 patients. A total of 63 lymph nodes in the 38 lung cancer patients were aspirated by TBNA with a positive rate of 65.1% (41/63). The sensitivity of TBNA was significantly correlated with pathology type, lymph node size and experience of the cytologist. Severe complications were rare except small amount of bleeding at the TBNA site (52/77, 67.5%). CONCLUSIONS TBNA is quite safe and helpful in diagnosis and staging of bronchogenic carcinoma, yet it is not helpful in diagnosis of benign lung diseases.