Intravenous injections of cefoxitin (2-g doses for adults and 40 mg/kg of body weight doses for children) were administered 90 minutes to two hours before surgery. All nine eyes had anterior segment inflammation. Samples of aqueous humor removed during surgery showed a mean cefoxitin concentration of 6.22 micrograms/ml, almost three times the concentration reported in uninflamed eyes. The greater penetration may have been the result of a breakdown in the blood-aqueous barrier. There were no complications.