A 47-year-old housewife presented with nonproductive cough, progressive breathlessness and intermittent fever during gold treatment, originally prescribed for seropositive polyarthritis, which later fulfilled the criteria for systemic lupus erythematosus (SLE). An open lung biopsy showed abundant interstitial edema with mononuclear inflammatory cells and some eosinophils, and slight bronchiolitis. The picture was nonspecific but suggestive of hypersensitivity pneumonitis. Electron microscopy revealed splitting and local disappearance of the basal laminae of the alveolar capillaries, venules and alveolar epithelium. This injury was confirmed by immunohistochemical staining for type IV collagen and laminin, the major components of basal laminae. In most macrophages there was lysosomal electron dense granular material, i.e. aurosomes, which gave the spectrum of gold in electron microprobe analysis. After the gold treatment was stopped the pulmonary symptoms gradually decreased during several months and no permanent lung disease remained. Whereas the pulmonary manifestation could have been due to her underlying disease we discuss in this study the possibility of its being gold induced.