In December 1989, a 72-year-old woman was hospitalized with atelectasis in the left lower lobe. The atelectasis resolved after bronchoscopic removal of impacted mucous plugs. Histopathological examination showed pulmonary mycosis. Microscopy suggested that a species of Aspergillus was responsible, but no definite diagnosis was made. After treatment with flucytosine and nebulized amphotericin, the patient's condition improved and she was discharged. In the middle of August 1994, she visited a local hospital complaining of fatigue. Eosinophilia (22%) was detected, and a few days later she visited that hospital again due to sudden dyspnea. A chest X-ray examination showed an abnormal shadow, and she was referred to our hospital. Atelectasis was seen in the left upper lobe. This finding, together with eosinophilia, suggested recurrence of pulmonary mycosis, and therefore bronchoscopy was performed. White mucous plugs obstructing the left upper lobe were observed and were bronchoscopically removed. Microscopical examination of the mucous plugs showed marked eosinophil infiltration and hyphae. Cultures of specimens obtained during bronchoscopy showed Schizophyllum commune, and allergic bronchopulmonary mycosis due to this microorganism was diagnosed. Identification of this microorganism as a cause of deep-seated pulmonary mycosis is very rare.