We report the first case of pacemaker endocarditis due to a new rod-shaped Neisseria sp. isolated from blood culture. On the basis of rrs sequencing, the isolate was found to be most closely related to an uncultured organism from human subgingival plaque and was identified as Neisseria sp. group AK105. A cure was achieved after a combination of surgical and antibiotic treatment. Oral flora-induced pacemaker endocarditis is a rare condition that reinforces the need for good oral hygiene as an important preventive measure.