Endogenous bacterial endophthalmitis is a diagnostic challenge both ocular and general, whose functional and vital prognosis can be severely engaged. The diagnosis is sometimes easy in case of occurrence on a predisposed ground (immunodepression, drug addiction, nosocomial infection) but litigious in the healthy subject. The presence of the fusobacterium nucleatum incriminated in the genesis of colon cancer and associated with a darker prognosis of cancer in vitreous fluid or in the piece of enucleation or evisceration should prompt us to launch a complete digestive balance to eliminate a colonic tumor. Diagnostic and therapeutic management must be rapid in order to avoid ocular and general complications potentially blinding or lethal.