OBJECTIVE. The purpose of this study is to assess the radiographic, thin-section CT, and histologic findings of semiinvasive aspergillosis in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS. The study included nine patients with COPD seen at the Hospital de Sant Pau during a 3-year period who had histopathologically proven as, pergillosis with tissue invasion. Chest radiography and thin-section (2-mm collimation) CT of the chest were available in all cases RESULTS. Nine patients had semiinvasive aspergillosis proven at autopsy (n = 7) or by thoracoscopically guided lung biopsy (n = 2). The radiologic findings consisted of parenchymal consolidation (n = 6) and nodules larger than 1 cm in diameter (n = 3). Parenchymal consolidation involved the upper lobes in five patients and was bilateral in four. Cavitation was present in two of the patients with consolidation and in two of the patients with nodular opacities. Adjacent pleural thickening was revealed by CT in four patients. Histologically, the areas of consolidation represented active inflammation and intraalveolar hemorrhage containing Aspergillus organisms. In the three patients with multiple cavitated nodules, a variable degree of central necrosis was observed. The inflammatory infiltrate extended into the surrounding lung parenchyma, and adjacent areas of hemorrhage were also seen. Aspergillus colonies were identified within the lung tissue. CONCLUSION. Upper lobe consolidation or multiple nodules in patients with COPD should raise the possibility of semiinvasive aspergillosis.