Radilologic finding of 81 cases of acute primary pneumonia in adolescence(in the twenties) were analyzed retropectively with regard to their pattern location evolution and complica-tion. The results were as follows; 1. The cases of single lesion were 85% and multiple lesion 15% 2. Left lower lobe was the most frequent site of involvement(42%) followed by right lower lobe(29%) right middle lobe(13%) left upper lobe (12.5%) and right upper lobe (4%) in the cases of single lesion. In cases of multiple lesions. lower lobe involvement was not so predominent as in cases of single lesion. 3. Most of the lesions were alveolar or bronchopneumonic in radiologic pattern. Interstitial pneumonic pattern was found in only 7 cases (9%) 4. Pleural effusion as associated finding was found in only 2 cases (2%) 4. Pleural effusion as associated finding was found in only 2 cases (2%) 5. Rapid radiographic improvement short clinical course complete healing without residue when treated with broad spectrum antibiotics seem to be different findings as compared with secondary or elder group pneumonia.