Eighty-three cases of endophthalmitis occurring in eyes with intraocular lenses are presented. A problem with the cataract section was felt to contribute to development of the endophthalmitis in 22% of patients. Seventy-five percent of eyes were culture positive with a microbiologic spectrum similar to other reported series without lens implants. Staphylococcus epidermidis was the most common organism accounting for 38% of the isolates. Therapeutic vitrectomy was performed in 46 cases (55%), generally in those eyes with the most severe inflammation. Intraocular lenses were removed in 23 cases (28%), usually to facilitate vitrectomy. Only 1 of 57 eyes with bacterial endophthalmitis could not be sterilized while the intraocular lens was retained. Visual acuity of 20/400 or better was achieved in 63% of culture positive cases, in 78% of eyes infected with S. epidermidis, and in 94% of culture negative eyes.