Background: Most cases of exogenous endophthalmitis occur after intraocular surgery. Although phacoemulsification is quick and convenient, there are some risks involved, and infection is one of them. This study investigated the associated factors and methods of prevention and treatment of endophthalmitis after phacoemulsification. Methods: A retrospective study was conducted of 84 497 phacoemulsification surgeries with intraocular lens implantation performed in the 10 branches of Mai Ge Ophthalmological Hospital, Tianjin, China, from 1993 to 2003. Results: It was found that 14 patients suffered from postoperative endophthalmitis in 14 eyes. Among them there were 5 cases with rupturing of posterior lens capsule. Postoperative endophthalmitis was culture-positive in 7 cases. After treatment, 5 patients had a visual acuity of 2.0 or above, 4 patients experienced the perception of light or hand movement, and the remaining 5 patients had lost light perception (2 cases ultimately had optic atrophy, and ophthalmectomy was performed on 3 eyes). Interpretation: Endophthalmitis after phacoemulsification surgery led to severe vision loss and blindness, although its incidence was low (0.02%) in this study. The most common organism isolated was Staphylococcus epidermidis, and rupturing of the posterior capsule was one of the main risk factors. Early diagnosis and treatment restored visual acuity in several cases, and improved phacoemulsification technique, including sterilization, helped reduce the incidence of endophthalmitis.