A patient with antecedent coccidioidal pulmonary cavitary disease who developed an empyema due to Kingella kingae prompted our analysis of the literature regarding this unusual bacterial pathogen. Formerly classified among other genera and considered a nonpathogen, K. kingae has been increasingly recognized as a cause of human infection. While the most commonly diagnosed infections due to this organism are endocarditis and septic arthritis, there have also been isolated reports of bacteremia, diskitis, abscesses, meningitis, and oropharyngeal infections. The treatment of choice is penicillin, to which K. kingae strains are uniformly susceptible. Recognition of the potential pathogenicity of this microorganism in appropriate clinical settings will probably result in more prompt and specific therapy.