This report describes a 69 year old woman, suffering from active rheumatoid arthritis since the age of 60 and presenting with severe dyspnoea and cough. A computed tomography scan of the chest showed multiple bilateral pulmonary nodules, sometimes cavitated, associated with reticular opacities and pleural effusion. A videothoracoscopic excision of a cavitated nodule was performed. Seven days after surgery, a right pneumothorax developed, and the patient died of septicaemia one month later. Microscopically, the excised nodule was composed of necrotic fibrinoid material with a peripheral rim of palisaded histiocytes, extending to the pleural surface and containing several fungal hyphae morphologically consistent with aspergillus. A diagnosis of pulmonary rheumatoid nodule with fungus colonisation was made. In the lung, fungus colonisation is a rare complication of rheumatoid nodules. The most important differential diagnostic considerations are briefly discussed.