A 62-year-old man was admitted to our hospital with complaints of coughing and fever. He had poliomyelitis at the age of 4 years, and had experienced difficulty in swallowing and chronic aspiration for the past 3 years. A chest roentgenogram and a high-resolution CT scan obtained on admission showed many small nodular shadows in the lower lung fields. Cricopharyngeal myotomy was done to decrease aspiration. The patient was then able to eat without aspiration, and the chest-roentgenographic and CT findings improved. Diffuse aspiration bronchiolitis was diagnosed from the clinical course and the radiographic findings. Cricopharyngeal myotomy can reduce the risk of aspiration in patients with diffuse aspiration bronchiolitis.