We performed a retrospective study of CT findings in 14 patients with 61 lesions of pulmonary infarction diagnosed clinically and radiographically. All cases except one had multiple pleural-based parenchymal lesions, and in five cases the lesions were bilateral. The site of pulmonary infarction was the right lower lobe in 24 lesions, left lower lobe in 19 lesions, right upper lobe and left upper lobe in seven lesions each, and right middle lobe in four lesions. Fifty-nine infarctions (excluding two segmental lesions) were divided into two groups according to the size of the lesions: a group of lesions 2 cm or more in size and a group less than 2 cm. Nineteen lesions in eight patients were in the larger group and 40 lesions in 12 patients in the smaller group. The typical CT findings of larger infarctions were pleural based parenchymal density with truncated apex, centrally directed linear shadow and inside low attenuation area indicating viable lung. Pleural thickening and effusion were frequently seen. No air bronchograms were seen in these subsegmental lesions. Smaller lesions were believed to indicate infarction of a single secondary pulmonary lobule, considering their size and shape. CT scan was able to detect these small lesions (single lobular infarctions) more frequently than chest radiography. One segmental lesion with air bronchogram was thought to represent atelectasis and the other one to represent pulmonary hemorrhage and edema. CT examination is useful for the detection and diagnosis of pulmonary infarction.