The clinical and radiologic manifestations of pulmonary aspergillosis depend on the underlying status of the patients' lung parenchyma and the patients' immunologic response to the infecting agent, most commonly Aspergillus fumigatus. Thus, many different manifestations of pulmonary aspergillosis have been described, with distinct clinical, pathological, and radiological characteristics. Aspergillomas (mycetomas) result from Aspergillus colonization of preexisting lung cavities. Allergic bronchopulmonary aspergillosis results from a hypersensitivity reaction to the fungus in asthmatic patients. Invasive aspergillosis occurs in immunocompromised patients and can take one of many forms, depending on the degree and etiology of the patients' immunosuppression. CT is currently the best imaging modality for the assessment of pulmonary parenchymal disease. In the correct clinical setting, the CT findings frequently suggest a specific diagnosis. The aim of this review is to discuss and illustrate the various CT manifestations of pulmonary aspergillus infection.