The diagnosis of necrotic herpetic retinitis is suggested on clinical grounds, prompting urgent appropriate intravenous and intravitreal treatment. PCR on ocular samples is most often successful in identifying the herpetic agent. Classic acute retinal necrosis syndrome caused by herpes simplex or zoster virus and the different clinical forms present in immunocompetent or immunodepressed patients are described. The differential diagnosis includes atypical presentation of retinal necrosis caused by toxoplasmosis, syphilis, or ocular lymphoma; the ocular samples are useful in establishing the etiological diagnosis. We describe the different therapeutic strategies in the acute phase and as secondary prophylactic treatment. The clinical outcome appears to be influenced by rapid, appropriate treatment, limiting the extension of the retinal necrosis.