Of 33 cases of Eikenella corrodens infection occurring in a general hospital during an 18-month period, 18 were related to human bites or fist-fight injuries, and nine of these 18 cases were complicated by septic arthritis and/or osteomyelitis. Because E. corrodens grows slowly, requires an atmosphere containing 5%-10% CO2, and may be overgrown by other organisms, it may be missed on routine culture. The high rate of recovery of the organism in this study was attributable to the use of a selective medium. Because infections due to E. corrodens commonly mimic or occur in association with anaerobic infections, they are sometimes treated inappropriately. E. corrodens should be considered a possible pathogen in infections associated with oral contamination. Empiric antibiotic treatment of these infections with clindamycin or metronidazole alone is inappropriate since E. corrodens is generally resistant to these agents.