AIM:To compare the effects of pre- and post- silicone oil removal combined phacoemulsification in silicone oil-filled eyes. METHODS: The clinical data of 36 patients (36 eyes) were analyzed. The 36 cataracts after silicone oil tamponade with pars plana vitrectomy were randomly divided into two groups. The two groups underwent combined phacoemulsification pre- and post-silicone oil removal respectively. The intraoperative and postoperative complications and postoperative anterior chamber reaction, intraocular pressure and corneal endothelium were observed. RESULTS:All patients operations were completed smoothly with silicone oil removal and IOL implantation, complications got effectively clinical control.The corneal endothelium cells densities and ratios of hexagonal cells were differently decreased.The ratios of hexagonal cells were significant difference between two groups of one week postoperatively. The corneal endothelial cell density and proportion of hexagonal cell were significant difference between two groups of one month postoperatively (P<0.05). CONCLUSION:The complications, anterior chamber reaction, and corneal endothelial lesion were less in group of pre-silicone oil removal combined phacoemulsification.