The frequency of bronchial and parenchymal involvement was studied in 44 patients with intrathoracic sarcoidosis by means of histologic and cytologic analysis of bronchial and pulmonary biopsies taken through bronchofiberscope. Endoscopy showed mucosal hyperemia with or without superficial granules in 59% of cases. Bronchial granulomatosis was found in 50% of cases at stages 0 and I, in 38% at stage II and in 42% at stage III. Epithelioid granulomas were seen in lung parenchym in 63% of cases at stages 0 and I, in 90% at stage II and 73% at stage III. Cytologic examination of bronchial brushings and biopsy imprints showed epithelioid and/or giant cells in 47% of cases at stages 0 and I, in 70% at stage II and in 68% at stage III. Cytology is therefore very useful in patients presenting with a clinical and radiological picture compatible with sarcoidosis. Bronchial and transbronchial lung biopsies represent the method of choice for obtaining histologic confirmation of intrathoracic sarcoidosis at all stages.