Six patients with asymptomatic primary pulmonary Cryptococcosis are reported. In all of the patients, the disease was detected by annual chest X-ray during mass screening for lung cancer or during follow-up for pulmonary tuberculosis or gastric cancer. The chest X-ray findings consisted of a solitary pulmonary nodule in 4 patients and multiple pulmonary nodules in 2. Only one patient who could not be histologically diagnosed by bronchofiberscopy underwent surgical resection. However, the other 5 patients were histologically diagnosed by transbronchial biopsy with bronchofiberscopy. They were treated with oral antifungal agents, namely flucytosine (5-FC) and/or fluconazole, with marked improvement of chest X-ray findings. These results indicate that transbronchial biopsy with bronchofiberscopy and oral administration of antifungal agents instead of initial surgical resection are useful in the diagnosis and treatment of primary pulmonary cryptococcosis.