Propionibacterium acnes is a slow-growing aerotolerant anaerobic gram-positive pathogen. Classically, it is associated with a chronic endophthalmitis, in which patients present with symptoms of anterior uveitis and a characteristic plaque is seen on the posterior lens capsule. In contrast, all 3 eyes described herein were completely quiet, without any clinical evidence of inflammation. We propose that the pronounced inflammatory reaction seen in chronic endophthalmitis secondary to P acnes is attributable to access of the organism to the anterior chamber, allowing the eye to react with an inflammatory response. In late CBS, there is an absence of inflammation, as the P acnes in the turbid fluid is sequestered within the capsular bag owing to the tight seal of the anterior capsule to the IOL. Interestingly, when this type of case is treated with an Nd:YAG posterior capsulotomy, the milky fluid can be visualized tracking into the vitreous cavity, and we have not yet observed inflammation or endophthalmitis. However, in 1988, Carlson and Koch3 did report a case of P acnes endophthalmitis after an Nd:YAG laser capsulotomy. Whether their patient had late CBS is unknown. In our experience with other such cases that were treated with an Nd:YAG laser, it seems that this turbid fluid, with its debris, is cleared quite effectively from the vitreous cavity without consequence. A possible explanation for this lack of inflammation is that the bacterial count is low, with a prolonged doubling time of P acnes, or perhaps the oxygenated vitreous serves as a poor culture medium for this anaerobic species. Alternatively, perhaps the anterior segment inflammation seen in chronic endophthalmitis is attributable to an immunologic phenomenon associated with P acnes infection.4 These cases bring into question the role of P acnes as a pathogen in late CBS and whether antibiotic therapy, topical or intravitreal, is actually indicated.