A retrospective chart review of all patients seen at the Cleveland Clinic Foundation with infectious endogenous endophthalmitis between January 1982 and August 2000 revealed 34 affected eyes in 27 patients. During this time, the median incidence of endogenous endophthalmitis was 1.8 cases/year, and 48.1% of patients presented as outpatients. Twenty-six patients presented to an ophthalmologist, and the diagnosis was initially missed in almost half the cases. Eleven patients had an unremarkable physical exam except for eye findings. We found an equal incidence of bacterial and fungal endophthalmitis and a predominance of among the fungal etiologic agents. We did not, however, note a predominance of Gramnegative organisms seen mostly in reports from Asia. The microbiologic diagnosis was based on aqueous and vitreous cultures or positive eye histopathology stains in almost two-thirds of cases. The sensitivity of the Gram stain was poor, but its specificity and positive predictive value were excellent. The vitreous cultures obtained by vitrectomy instruments were more sensitive in making the diagnosis than the vitreous needle biopsy. Aside from blood cultures and eye specimen cultures, half the patients had an additional infectious focus, most frequently a urinary tract infection, whereas infectious endocarditis was seen in a small minority. Twelve patients had visual improvement with treatment with a final visual acuity better than 20/200 in 44% of the eyes. Good visual outcome was associated with visual acuity of 20/200 or better at diagnosis and with the absence of hypopyon.