Herpes viruses represent a major etiology of retinitis and their implication should always be taken into consideration in typical clinical presentations. Primary infection by members of this family is usually efficiently controlled by the immune system. Diagnostic confirmation is a major issue and allows specific therapeutic strategies based on antivirals and, sometimes corticosteroids. Herpes viruses can be transmitted to a susceptible individual following close contact with the secretions, skin, or mucous membranes of an infected person shedding virus. Infections with herpes viruses are very common in the general population, but in most cases they do not cause clinically apparent disease. Ocular herpes simplex virus type 2 infection seems to spread via an oculogenital route in the majority of cases. Animal models have been developed to define the main characteristics of viral retinitis. Human cytomegalovirus has a different pattern of replication than that of HSV and VZV. Pertinent permissive cell cultures, such as retinal glial cells or retinal pigment epithelial cells, have been used to study HCMV replication. Necrotizing viral retinopathies have been described and largely characterized by electron microscopic studies, immunocytochemistry, viral culture from intraocular specimens, serologic analysis of serum and/or intraocular fluids, and, finally, by the polymerase chain reaction. The acute retinal necrosis (ARN) syndrome is characterized by acute primarily peripheral, necrotizing retinitis, retinal arteriolitis and mild to severe vitritis. The disease is usually unilateral and is known to be caused by VZV, HSV, but rarely by CMV. The diagnosis of herpetic intraocular inflammation is initially based on the analysis of clinical features. Laboratory tests can help the clinician confirm the disease. The amount of ocular fluids is a limiting factor to perform diagnostic tests in patients with a suspicion of viral intraocular inflammation. Vitreous fluid analysis has to be considered in both inflammatory conditions that do not respond to treatment and in masquerade syndromes.