The patient was a 27-year-old man, whose chest CT scan showed a nodular shadow on the right lower lobe while he worked as a volunteer in Nicaragua. After he returned to Japan in February 2011, he was admitted to our hospital for further evaluation. Because his bronchoscopic examination did not provide a definitive diagnosis, the patient underwent CT-guided lung biopsy. The aspirated fluid did not show any malignant cells, but it did show large amounts of leukocytes. From the sample cultures, Capnocytophaga sp. was isolated, and Capnocytophaga sputigena was identified using 16S rRNA gene analysis. The patient was diagnosed with lung abscess caused by C. sputigena, and underwent antimicrobial therapy. A follow-up chest CT scan one year later showed only a scar-like lesion. C. sputigena, isolated and identified from respiratory specimen culture, has previously been shown in only 1 case in the French literature. This is the first case report in Japan showing a respiratory infection resulting from C. sputigena, though we cannot rule out the potential mixed infection with other pathogens. To clarify the pathogenic significance of Capnocytophaga spp. in respiratory infections, more cases needed to be analyzed.