OBJECTIVE To explore the effects of vitrectomy combined with silicone oil injection on the treatment of postoperative endophthalmitis following cataract surgery without intraocular lens removal, and to analyze the relative factors. METHODS This was a retrospective case series study. Clinical data of 7 eyes of 7 patients with postoperative endophthalmitis following cataract surgery underwent the treatment of vitrectomy combined with silicone oil injection without intraocular lens removal from 2003 to 2008 were collected. The outcomes of vision, slit lamp examination, direct and indirect ophthalmoscopy, IOP, and B-scan were observed, and the surgical effects were analyzed. RESULTS Five patients were male, and 2 patients were female. The age ranged from 67.0 to 84.0 years with a mean of 70.0 + or - 4.5. The onset of endophthalmitis ranged from 1 to 3 days with a mean of 2 days. Silicone oil was removed in 5 eyes 3 to 6 months postoperatively. Preoperative visual acuity ranged from non light perception to hand moving. The mean preoperative intraocular pressure (IOP) was (35.0 + or - 0.5) mmHg with a range from 35.0 to 56.0 mmHg. Follow-up periods ranged from 6 to 43 months with a mean of (10 + or - 6) months. Postoperative visual acuity ranged from non light perception to 0.8. Postoperative vision increased in 6 eyes (86%), and was stable in 1 eye (14%). The mean postoperative IOP was (18.0 + or - 1.5) mmHg with a range from 10.0 to 20.0 mmHg, this was significantly lower than that preoperatively (t = 1.94, P < 0.05). Postoperative complications mainly included fibrous exudates in the anterior chamber at early stage after the surgery (7 eyes) and temporary intraocular pressure elevation (1 eye). There was no retinal detachment and atrophia bulbi. CONCLUSIONS Vitrectomy combined with silicone oil injection may be a safe and effective method in treating postoperative endophthalmitis following cataract surgery without intraocular lens removal.