To investigate the clinical settings, management strategies, antibiotic sensit ivities, and visual acuity outcomes for eyes with endophthalmitis caused by Haem ophilus influenzae. Retrospective, noncomparative, consecutive case series. The medical records were reviewed of all patients treated for culture proven H. inf luenzae endophthalmitis at a single institution between January 1, 1980, and Dec ember 31, 2002. Visual acuity and antibiotic sensitivities. The study included 1 6 eyes of 16 patients with a median age of 68 years (range, 6 months-83 years) and a median follow up of 26 months (range, 2 months-15 years). Clinical setti ngs included post trabeculectomy (n=7), postcataract surgery (n=6), post pars plana vitrectomy (n=1), post secondary intraocular lens insertion (n=1), and po stsuture removal from an extracapsular cataract wound (n=1). Eleven (69%) cases were of delayed onset ( > 6 weeks from surgery/event), with a median interval b etween surgery/event and presentation with endophthalmitis of 18 months (range, 44 days-21 years); 5 (31%) cases were of acute onset (median, 6 days; range, 2 -14 days). Presenting visual acuity was hand movements or better in 7 (44%) ey es. A vitreous tap and inject was performed initially in 9 (56%) eyes, and a vi trectomy was performed initially in the remaining 7 (44%) eyes. All eyes receiv ed intravitreal antibiotics on the day of presentation, and 11 (69%) received i ntravitreal dexamethasone. In vitro testing of the H. influenzae isolates reveal ed that 14 of 16 (88%) were sensitive to vancomycin, ampicillin, and trimethopr im/sulfa methoxazole; 15 of 16 (94%) were sensitive to aminoglycosides (1 isol a te was resistant to gentamicin); and all were sensitive to cephalosporins, fluor oquinolones, and carbapenems. The organisms were sensitive to at least 1 of the initial antibiotics administered in all cases. Final visual acuity was 5/200 or better in 6 (38%) eyes, and 6 (38%) eyes had a final visual acuity of no light perception. Endophthalmitis caused by H. influenzae is generally associated wit h poor visual outcomes despite prompt treatment with intravitreal antibiotics to which the organisms were sensitive. To investigate the clinical settings, management strategies, antibiotic sensitivities, and visual acuity outcomes for eyes with endophthalmitis caused by Haem ophilus influenzae. Retrospective, noncomparative, consecutive case series. The medical records were reviewed of all patients treated for culture proven H. inf luenzae endophthalmitis at a single institution between January 1, 1980, and Decmber 31, 2002. Visual acuity and antibiotic sensitivities. The study included 16 eyes of 16 patients with a median age of 68 years (range, 6 months-83 years) and a median follow up of 26 months (range, 2 months-15 years). Clinical setti ngs included post trabeculectomy (n = 7), postcataract surgery (n = 6), post pars plana vitrectomy Eleven (69%) cases were of delayed onset (> 6 weeks from surgery / event), with a median interval b etween surgery / event and presentation with 5 (31%) cases were of acute onset (median, 6 days; range, 2 -14 days). Presenting visual acuity was hand movements or better in 7 (44 %) ey es. A vitreous tap and inject was performed initially in 9 (56%) eyes, and a vi trectomy was done initially in the remaining 7 (44%) eyes. All eyes receiv ed intravitreal antibiotics on the day of presentation, In vitro testing of the H. influenzae isolates reveal ed of 14 of 16 (88%) were sensitive to vancomycin, ampicillin, and trimethoprim / sulfa methoxazole; 15 of 16 (94% ) were sensitive to aminoglycosides (1 isol a te was resistant to gentamicin); and all were sensitive to cephalosporins, fluor oquinolones, and carbapenems. The organisms were sensitive to at least 1 of the initial antibiotics administered in all cases. Final visual acuity was 5/200 or better in 6 (38%) eyes, and 6 (38%) eyes had a final visual acuity of no light pereception. Endophthalmitis caused by H. influenzae is generally associated wit h poor visual outcomes in prompt treatment with intravitreal antibiotics to which the organisms were sensitive.