A 26-year-old man was admitted to our hospital for evaluation of cavitary lesions on his chest X-ray film. Chest CT and conventional tomograms showed multiple cavities in both lung fields, as well as hilar and mediastinal lymphadenopathy. He had uveitis and the laboratory data showed a high level of angiotensin converting enzyme in the serum. Histological findings of the specimen obtained by transbronchial lung biopsy showed non-caseating epithelioid cell granuloma, consistent with sarcoidosis. Corticosteroid therapy (prednisolone 40 mg/day) resulted in reduction of the cavitary lesions and the lymphadenopathy. Negative bacteriological studies and the clinical course strongly suggested primary cavitation, a relatively rare form of pulmonary parenchymal involvement in sarcoidosis.