Septic olecranon bursitis (OB) is caused primarily by Staphylococcus aureus (SA) usually in association with occupations involving trauma to the elbows. An outbreak of septic OB was identified in an infantry platoon. The severity of the injury to the skin overlying the elbows was scored and compared to a parallel platoon of the same unit. All soldiers were tested for SA carriage and pulse field gel electrophoresis (PFGE) was performed on available isolates. Nine cases of septic OB were identified only in platoon A. The significant risk factor for septic OB was a moderately or severely injured elbow (RR = 3.86). SA was isolated from the anterior nares and elbows of 29/36 (80.6%) of the soldiers in the unit (platoons A + B); however, this did not account for the difference in morbidity between the two platoons. This is the first report of a cluster of septic OB in association with intense infantry training.