Recently there is an increased incidence of tuberculous mediastinal lymphadenitis in adults. The authers analyzed 45 proven cases of tuberculous mediastinal lymphadenitis that had presented with a mediastinal or hilar mass on plain chest radiography. The results were as follows : 1. Total 45 cases were 20 males and 25 females. The 3rd decade (51.1%) was the most prevalent age group. 2. The most common clinical symptom was fever(53.3%) followed by cough (48.9%) and weight loss (35.6%) And 5 cases (11.1%) were symptom-free. 3. The most frequently identified involving site was right lower paratracheal node in 31 cases (68.9%). And right upper paratracheal node involvement and right tracheobronchial node involvement were 19 cases (42.4%) and 16 cases (35.6%) respectively. Unilateral nodal involvement (66.7%) was more common and right side predominence (80%) was noted. 4. Mediastinal lymph node enlargement without pulmonary parenchymal infiltrates were 11 case (24.4%) Associated pulmonary infiltration were noted in 26 cases (57.7%) and pleural involvement was noted in 12 cases (26.7%). The possibility of tuberculous mediastinal lymphadenitis should be initially considered in the differential diagnosis of mediastinal lymphadenopathy on simple radiographs of young and old adults especially in the presence of parenchymal infiltrations and/or pleural involvement.