Between 1987 and 1992, nine patients (three men and six women; mean age, 75 years) presented with chronic postoperative endophthalmitis after cataract extraction and intraocular lens (IOL) implantation. Eight patients were referred from another institution. The interval between IOL implantation and the beginning of intraocular inflammation averaged 5.6 months (range, 1-19 months). The referral diagnosis was "toxic lens" syndrome in seven patients. The main clinical findings were a hypopyon in the anterior chamber (n = 8) and in the capsule bag (n = 2), and "fibrosis" of the lens capsule (n = 7). In eight patients a vitrectomy was performed, combined with removal of the IOL in six cases and with a total posterior capsulectomy in five cases. Pathogenic organisms were identified in vitreous aspirate (6/8), in culture (3/3), and on histopathological examination (4/5) of lens capsule and included coagulase-negative staphylococci (n = 3, Staphylococcus epidermidis), Propionibacterium acnes (n = 1), Streptococcus viridans (n = 1), Rhodococcus erythropodes and R. luteus (n = 1), and one hyphomycete (Alternaria alternata). In chronic recurrent intraocular inflammations following IOL implantation, an infectious agent should be excluded by diagnostic and therapeutic pars plana vitrectomy including removal of the IOL and posterior capsulectomy.