Corneal endotheliitis is an intriguing clinical entity manifested by corneal edema, keratic precipitates, and mild anterior chamber reaction, and can be defined as a spectrum of the disorder in which the corneal endothelium is the primary site of the inflammation. The disease etiology consists of accumulating evidence of various viral infections including herpes simplex virus, varicella zoster virus, and cytomegalovirus. Corneal endotheliitis can be classified clinically into four forms: linear, sectorial, disciform, and diffuse. Antiviral treatment in combination with topical corticosteroids is generally effective to suppress the inflammation; however, irreversible corneal endothelial dysfunction may develop in some cases.