Purpose: Clinical and histopathologic documentation of sympathetic ophthalmia (SO) development in eyes with postoperative bacterial endophthalmitis. Design: Observational case series; retrospective clinicopathologic study. Methods: All patients who presented with a clinical diagnosis of SO during 2002 to 2004 were included in the study. The diagnosis of SO was made on the basis of history of penetrating ocular injury, followed by development of bilateral intraocular inflammation, ultrasonographic detection of bilateral diffuse thickening of the choroid, or both. Patients presenting with the additional finding of hypopyon underwent an anterior chamber tap and vitreous aspirate for microbiologic detection of bacteria and fungi. Eight exciting eyes were enucleated and submitted for histologic examination. Results: Of a total of 26 patients with a clinical diagnosis of SO, four also had bacterial endophthalmitis. Of these, histologic examination of three exciting eyes revealed vitreous abscess and typical features of SO. Of the five remaining enucleated globes, histologic examination showed that two eyes had phacoanaphylactic endophthalmitis, and two others revealed features of SO; the one remaining eye had nongranulomatous diffuse choroiditis. Conclusions: Bacterial endophthalmitis cannot prevent the development of SO. Early diagnosis of coexistent mixed infectious and inflammatory processes, and initiation of antimicrobial treatment directed at the infection followed by immunomodulatory agents to address the autoimmune component may improve the prognosis in such cases. [Copyright &y& Elsevier]