The level of cytosolic glucocorticoid receptors (GR) was measured in 12 open-chest lung biopsies of interstitial pulmonary diseases. The results showed an increase in the GR content in the diseased lungs correlated to the degree of septal cellularity in nine cases. Two pulmonary sarcoidosis and one end-stage idiopathic pulmonary fibrosis patients presented higher levels of GR than those predicted by the septal cellularity. It was concluded that the GR content of the lungs increases in the course of interstitial diseases, reflecting the number of cells that express cytosolic GR in pulmonary parenchyma.