Acute retinal necrosis (ARN) is increasingly being observed among patients with HIV infection. Varicella-zoster virus (VZV) and herpes simplex virus (HSV) are recognized as being the etiologic agents in this syndrome. Among the 538 patients with HIV infection (261 of these with AIDS), who were followed up in our department between 1985 and 1990, we diagnosed ARN in 4 cases. Three of these patients suffered from AIDS. Thus, ARN was the third-most-frequent form of retinitis in our patients with AIDS (prevalence 1.1%), following Cytomegalovirus (CMV) retinitis (17.2%) and toxoplasmosis-retinochorioiditis (2.7%). The course of ARN in patients with AIDS is demonstrated in four case reports. Special features of the retina are documented by photographs of the fundus. The authors suggest that patients with AIDS who experienced an episode of VZV- or HSV infection which necessitated high-dose systemic aciclovir therapy are at risk of developing ARN. We recommend that they be kept on virustatic maintenance therapy.