A 78-year-old Japanese woman without any history of asthma or smoking presented prolonged cough. Laboratory data showed elevated serum CEA levels and a chest CT revealed a mass with abnormal uptake in the left lower lobe. One month later, the mass spontaneously regressed, and CEA levels improved. However, the symptoms progressed during the observation period without treatment. Chest radiograph findings revealed collapse of the right middle lobe, and Schizophyllum commune was isolated from the mucous plugs; the patient was diagnosed with allergic bronchopulmonary mycosis (ABPM). Herein, we report the first case of ABPM caused by S. commune with elevated CEA levels and mimicking lung cancer.