Between March 1993 and September 1994 we treated 25 cases of lenses in the vitreous cavity. Nineteen of the 25 were the result of dislocation during phacoemulsification. During this time, we adopted a single surgical algorithm involving vitrectomy, heavy liquids and ultrasound fragmentation. The aims of this retrospective study were to test the validity of our surgical algorithm and to report on outcomes and complications. The indications for vitreous surgery were raised intraocular pressure, uveitis and poor vision. Vitreous surgery was carried out at a mean of 29 days following phacoemulsification. Six patients required heavy liquids and 5 needed ultrasound fragmentation. Vitreous surgery undertaken less than 17 days after phacoemulsification had an increased likelihood of requiring heavy liquids and/or fragmentation (p < 0.02). The greatest threat to a favourable visual outcome was retinal detachment, which was significantly associated with fragmentation and use of heavy liquids (p < 0.02). The presence of an intraocular lens (IOL) reduced the surgical options for removal of the lens fragments, and IOL should not be inserted where lens matter dislocates. The study suggests that we should avoid fragmentation and, provided the intraocular pressure and uveitis can be controlled, that vitreous surgery should be deferred for 2-3 weeks following phacoemulsification.