We reviewed the medical records of four patients with marked intraocular inflammation and hypopyon as the initial manifestation of retained lens fragments after phacoemulsification. The severe inflammatory reaction occurred between one month and one year after the cataract extraction. All four patients underwent pars plana vitrectomy to remove the lens fragments. The vitreous specimens were cultured to rule out infectious endophthalmitis. In all patients, no organisms were isolated from the vitrectomy specimens placed on both aerobic and anaerobic media. All patients had improved vision and resolution of the marked intraocular inflammation after vitrectomy. Echography was useful in establishing the diagnosis in these uncommon cases.