Authors analyzed 21 cases of CT findings of radiation-induced pulmonary injury. Alveolar consolidation and partial fibrotic change of the irradiated field were early manifestation followed by total fibrotic change atelectatic change and bronchiectasis. The most common finding was fibrotic change (15 cases) Early appearance and augmentation of pulmonary injury were noted in combined chemotherapy. CT is useful for the detection of subtle change of early radiation pneumonitis and for the evaluation of the large area of increased density within the irradiated field on plain chest radiograph.