Primary pulmonary tuberculosis is one of the common pulmonary disease affecting children in Korea. Simple chest film is essential in diagnosis of primary pulmonary tuberculosis, but it is difficult to interpret the findings in some cases. Authers reviewed chest films of 162 cases of clinically confirmed primary pulmonary tuberculosis from April 1978 to June 1981 at Seoul National University Hospital. The results are as follows: 1. Lymph node enlargement, either hilar or mediastinal, was found in 82.7% and pulmonary parenchymal infiltration in 74%. 2. Incidence of unilateral and bilateral hilar lymph node enlargement is about 50% (80 cases) and 30% (49 cases) respectively. Incidence of unilateral and bilateral mediastinal lymph node enlargement is about 21% (34 cases) and 43% (7 cases), more common in right side. 3. Pulmonary parenchymal lesion is demonstrated in 74% (120 cases). The pattern of primary focus is as follows in order : patchy infiltration 47% (76 cases) linear-streaky infiltration 15% (25 cases), lobar or segmental homogenous infiltration 9% (14 cases), nodular infiltration 4% (7 cases). The primary focus of right lung is two times as common as that of left. 4. Calcification in primary focus is noted in about 27% in pulmonary parenchyme and 49% in hilum. 5. Pleural effusion is identified in 10%, but pleural effusion without pulmonary parenchymal lesion or lymph node enlargement is noted in only 2% (3 cases).