We report five cases of post-extracapsular cataract extraction infection in which subsequent pathologic analyses identified the organisms and found the infection to be localized or confined to the lens capsular sac. The most common offending organisms were gram-positive pleomorphic bacilli. In one case, we were able to identify the bacteria as Propionibacterium acnes. We designate this condition a localized endophthalmitis. It should be considered any time a persistent, smoldering, postoperative inflammation occurs, and in the differential diagnosis of phacoanaphylactic endophthalmitis. The condition itself is not new, but undoubtedly many such cases have gone unrecognized or have been misdiagnosed as the so-called toxic lens syndrome. In localized endophthalmitis, a clinically visible inflammatory process may occur even when multiple diagnostic taps are negative, although when the cases first appeared, the surgeons were not aware of the entity and anaerobic cultures were not always obtained. A negative tap may be explained by the fact that metabolic products from the organisms are released from the bag into the anterior segment and vitreous. A synergistic reaction may occur between these organisms and retained lens cortical remnants that may cause or exacerbate a hypersensitivity reaction. The condition may be worsened by Nd:YAG capsulotomy. The pathogenesis of localized endophthalmitis has nothing to do with the type of intraocular lens fixation (lens capsular sac or ciliary sulcus); rather, the simple presence of a capsular sac after extracapsular cataract extraction is the prerequisite for the clinical condition.