A 68-year-old woman, who had been healthy until this event, presented with a complaint of productive cough since 2000. She went to a neighboring hospital because of bloody sputum in October 2001. Although chest radiograph showed abnormal findings then, she received only an expectorant and cough remedy. She consulted us complaining of dyspnea on exertion in April 2005. Chest radiograph revealed cavity formation, bronchiectasis and a nodular shadow, and her condition had deteriorated. Microbiologically, acid-fast bacilli were detected three times in the culture of sputum, and Mycobacterium gordonae was identified by the biochemical method. However, this Mycobacterium gordonae could not be identified by the DNA-DNA hybridization method. Our case also probably was considered to be a primary type pulmonary nontuberculous infection because of her clinical course. In addition, we recognized that pulmonary M. gordonae infection also worsens without the therapy.