Antibiotics were administered intravitreally to 26 patients with culture-verified endophthalmitis. Vitrectomy surgery was combined with intravitreal antibiotic therapy in 14 of the cases. Pretreatment selection into a vitrectomy or nonvitrectomy group was determined by the duration of the disease, type of predisposing injury, and echographic findings. This diagnostic-treatment grouping allowed management to be initiated on the basis of the existing and potential virulence of the infecting process. The less virulent and often successfully managed Staphylococcus epidermidis accounted for 67% of cases in the nonvitrectomy group and only 14% in the vitrectomized series. During a mean follow-up period of 32 months (range, one to five years), retinal changes were monitored by visual acuity determination, electroretinography, and fluorescein angiography. An overall visual improvement (greater than or equal to 20/400) was found in 73% of the eyes treated. The causes for failure in the remaining cases may be related to retinal damage from the initiating trauma, organism response, and intraocular antibiotic therapy.