A case of posterior lens capsular abscess occurring many months after an extracapsular cataract extraction is presented. This was caused by a mixed infection involving Propionibacterium acnes and Staphylococcus epidermidis. The significance of Staph epidermidis after such a long postoperative period is uncertain, but the case shows features typical of secondary endophthalmitis due to P acnes, including a long delay in onset and a grumbling course not brought under control by medical treatment. It supports the theory that the nidus of infection is localised in the posterior lens capsule by showing development of a visible capsular abscess with associated vitreous involvement. The subsequent removal of the capsule and vitreous, despite leaving the intraocular lens in place, led to complete resolution of the inflammation. Both organisms have previously been found to be sequestered in the posterior lens capsule by histological and microbiological examination of excised capsular specimens. It is important to consider them as possible causative agents in the formation of a postoperative capsular abscess.