A case of symptomatic Actinobacillus actinomycetemcomitans bacteremia in a patient with an implanted pacemaker is presented. Attacks of fever occurred for at least 1 year. Oral examination revealed a mild form of periodontitis. A. actinomycetemcomitans was isolated from several oral sites. DNA fingerprinting of strains from the blood and the oral cavity showed identical profiles. This finding strongly suggests that the oral cavity was the primary source of A. actinomycetemcomitans bacteremia in this case. The patient was treated with the combination of metronidazole plus amoxicillin for 7 days, which resulted in a rapid cure and elimination of A. actinomycetemcomitans from the blood and the oral cavity.