Intrathoracic disease in AIDS-related lymphoma (ARL) produces a range of radiographic appearances. This study aimed to determine the frequency, distribution and characteristics of these appearances. The case notes and findings on imaging of 116 consecutive cases of ARL were reviewed retrospectively. In 52 cases there were abnormalities present on chest imaging (chest radiography or chest CT scanning). In 20 patients abnormalities were judged to be due to lymphomatous involvement and in 15 cases the thorax was the major site of disease. Correlation with biopsy results from thoracic disease (9), other disease (5), or evidence of response to treatment (6) was made. The most frequent imaging findings were pleural or intrapulmonary masses (7), frequently peripheral and sometimes with cavitation. In one case this simulated mycetoma formation. Pleural effusions and mediastinal lymph nodes were also frequently present, either alone or in combination. AIDS-related lymphoma uncommonly involves the chest as a major site of disease. A pleural or intrapulmonary mass with cavitation may represent the only site of disease and in these cases CT guided biopsy is likely to provide the histological diagnosis.