OBJECTIVE To report the clinical course, treatments, antibiotic sensitivities, and visual outcomes for eyes with ulcerative keratitis caused by Haemophlilus influenzae. METHODS The medical records of 10 patients with culture-proven H. influenzae-associated corneal ulcer in a tertiary referral center in a 5-year period (1998-2003) were retrospectively reviewed. RESULTS The median age was 61 years (range, 2-83 years). The mean follow-up time was 9.4 months (range, 2-31 months). Risk factors such as previous surgeries (5), herpes simplex keratitis (2), leukoma adherens with calcification (1), and exposure keratitis (1) were identified in 9 patients. In vitro testing of the H. influenzae isolates showed that 6 of 10 were resistant to ampicillin; all were sensitive to amoxicillin/clavulanic acid, ceftriaxone, and cefuroxime. All cases responded well to medical antibiotic treatment. Final best spectacle-corrected visual acuity ranged from no light perception to 20/30. CONCLUSIONS H. influenzae is a rare cause of corneal ulceration. Predisposing factors for infection are usually present. Accurate diagnosis and treatment may preserve ocular integrity and visual acuity.