Aggregatibacter actinomycetemcomitans is commonly part of the normal microflora of the human upper respiratory tract. It has been implicated in periodontal disease and various infections, particularly endocarditis. We report here what we believe to be the first case of recurrent infective endocarditis due to A. actinomycetemcomitans in a 44-year-old woman occurring 5 years after the initial episode. Genomic analysis proved that the strains were closely related. Despite efficient antibiotic treatment, surgery was necessary for recovery.