Acute retinal necrosis (ARN) syndrome, also known as Kirisawa's uveitis, is one of the most serious ocular diseases, and is characterized by a combination of peripheral, confluent, necrotizing retinitis, retinal arteritis, and intraocular inflammation. ARN syndrome is caused by the herpesvirus family, including herpes simplex virus (HSV) and varicella-zoster virus (VZV). The diagnosis of ARN syndrome is fundamentally based on clinical appearance and the demonstration of viral infection. Recently, polymerase chain reaction techniques permit detection of very small amounts of viral DNA in intraocular specimens. This knowledge can help in both the diagnosis and design of therapeutic strategy for ARN syndrome. Here we review the clinical presentation and the current advances in the diagnosis of ARN syndrome.