A 75-year-old man had clear corneal phacoemulsification using a temporal approach in the left eye. Two months after surgery, a focal corneal epithelial defect developed with infiltration near the lower limbus on the site of the side-port incision. The culture of corneal scrapping grew Acinetobacter baumannii, which is resistant to most ordinary antibiotics in sensitivity tests. After appropriate antibiotic treatment, the ulcer healed gradually with vessel ingrowth. Acinetobacter baumannii is usually found in nosocomial infection of immune-compromised patients in the intensive care unit. It is a rare pathogen of infectious keratitis. Our case, with its unusual infection site, may point to potential risk factors for this pathogen.