Radilogic findings of 81 cases of acute, primary pneumonia in adolescence (in the twneties) were analyzedretrospectively with regard to their pattern, location, evolution and complication. The results were as follows;1. The cases of single lesion were 85%, and multiple lesions 15%. 2. Left lower lobe was the most frequent site ofinvolvement (42%), followed by right lower lobe (29%), right middle lobe (13%), left upper lobe (12.5%) and rightupper lobe (4%) in the cases of single lesion. In cases of multiple lesions, lower lobe involvement was not sopredominent as in cases of single lesion. 3. Most of the lesions were alveolar or bronchopneumonic in radiologicpattern. Interstitial pneumonic pattern was found in only 7 cases (9%). 5. Rapid radiographic improvement, shortclinical course, completer healing without residue when treated with broad spectrum antibiotics seem to bedifferent findings as compared with secondary or elder group pneumonia.