Purpose : To describe the radiologic findings of pulmonary endometriosis. Materials and Methods : This studyinvolved five patients with catamenial hemoptysis diagnosed as pulmonary endometriosis. All cases were diagnosedon the basis of bronchoscopic abnormalities. In one patient, endometrial glandular cells were seen ontransthoracic fine needle aspiration biopsy. In three, hemoptysis ceased after Danazol treatment. The pattern,location and number of parenchymal abnormalities and the presence or absence of pleural lesion were analyzedretrospectively on plain chest radiographs (n=5) and CT scans(n=5). Follow-up study for each menstrual period wasperformed in two cases and changes from the initial lesion were assessed. Results : Plain chest radiographicfindings showed focal ground-glass opacity in three cases ; two were in the right lung and one in the left. CTfindings included ground-glass attenuation (n=3) and a mixed pattern of ground-glass attenuations andconsolidations(n=2). Sites were single in four cases, and in one case, there were two ; thus there were in all sixlesions. Five of these were located in the right lung and subpleural region, continving to the pleura. Pleurallesion was not detected on either chest radiographs or CT scans. Follow-up CT scans (n=2) showed a similar lesionat the same site. Conclusion : In patient with repeated catamenial hemoptysis, CT may be helpful for the diagnosisof pulmonary endometriosis by exclusion of other diseases.