Eight patients with aseptic cavitation of sterile pulmonary infarcts are described. All except one had left ventricular failure and/or chronic airflow obstruction. Infarcts with cavities were commonly single (75%) and right-sided (69%) and usually followed a sizeable area of consolidation (larger than 4 cm) after about 2 weeks. Of the 62% that could be localised to a segment, all were in the apical or posterior segment of an upper lobe or the apical segment of a lower lobe and the majority (85%) had scalloped inner margins and cross cavity band shadows. At the time of cavitation, 38% had additional features on the chest radiograph that were suggestive of pulmonary embolic disease. A number of cavities developed a tertiary infection and an air-fluid level but the latter feature was non-specific. Aseptic cavitation of a sterile pulmonary infarct should be considered in the differential diagnosis of any cavitating lung lesion, particularly if it shows the above features.