Endocarditis and unilateral endophthalmitis due to Actinobacillus actinomycetemcomitans heart disease. The ocular infection was notable for its localized presentation and slow evolution. Treatment with systemic, subconjunctival, and topical gentamicin sulfate and ampicillin sodium achieved 20/20 acuity with a residual chorioretinal scar in the nasal periphery. Intravitreal injection of the organism into a rabbit confirmed its minimal pathogenicity within the eye. This organism must now be considered in patients with differential diagnosis of endogenous endophthalmitis complicating endocarditis and septicemia.