Basing on observations of 960 patients with pulmonary sarcoidosis the authors found fibrotic changes of pulmonary parenchyma in only a few, the incidence being 3.2. Improvement in radiological examination following steroid therapy was seen in 50%, of respiratory function in 30%. Although both examinations do not fully correlate with each other, they are however supplementary with each other, and should be regarded as important criteria of functional involvement and therapy outcome.