An 83-year-old woman, who was diagnosed as chronic obstructive lung disease for years, was admitted to our hospital for the treatment of pneumonia. Bronchiectasis, centrilobular small nodular shadows, and sinusitis were observed by head and chest computed tomography. Further examination was performed after treatment of pneumonia. Spirometric analysis showed combined ventilatory impairment. The electron microscopic examination of bronchial biopsy revealed defect of the inner dynein arm of the mucosal cilia, resulted in the diagnosis of primary ciliary dyskinesia (PCD). Her symptoms, pulmonary function, and chest X-ray shadows improved by treatment of low-dose clarithromycin. Her clinical course was assessed by spirometry and forced oscillation technique (FOT). This case implicated the efficacy of low-dose clarithromycin on treatment of PCD and usefulness of FOT on the assessment of the treatment of PCD.