Endophthalmitis after cataract surgery can be a disastrous complication that may result in functional loss of an eye. All patients with this problem should receive direct injection of intravitreal antibiotics. The roles of initial vitrectomy and of intravenous antibiotics in treating this condition are controversial. Through a prospective, randomized, clinical trial, these issues can be assessed. We encourage ophthalmologists close to each clinical center to refer patients with postoperative endophthalmitis to these clinics. Questions concerning the Endophthalmitis Vitrectomy Study can be addressed to the principal investigator at the nearest clinical trial center.