Acute retinal necrosis syndrome (ARN) is a rare retinitis caused by the herpes virus family, including herpes simplex virus and varicella zoster virus. ARN most commonly occurs in otherwise healthy patients of either sex at any age. It is characterized by an initial onset of episcleritis or scleritis, periorbital pain, and a frequently granulomatous anterior uveitis. The key criterion is a necrotizing retinitis starting in the periphery and spreading towards the posterior pole, associated with vitreous opacification. Optic neuropathy may also occur. A total of 75% of untreated eyes develop retinal detachment within the first two months after onset of the disease. Two out of three ARN cases show involvement of the fellow eye. Early intravenous antiviral therapy is mandatory to stop ARN progression. Peripheral retinal breaks can be treated by laser photocoagulation, thereby reducing the risk of retinal detachment. Vitreoretinal surgery is often required, and silicon oil is the tamponade of choice in ARN, resulting in good reattachment rates (90%). Visual prognosis, however, is guarded.