The paper documents the cumulating appearance of 3 cases of the acute retinal necrosis (ARN) during one-year period at the district (local) eye department. It concerns the etiology, the treatment, evaluates its results and reveals the recommendations for the clinical practice.retrospective study.The ARN was diagnosed in 3 patients (2 woman and 1 man) at the age of 29, 43, and 58 years. Uveitis was unilateral in all cases. All three patients were treated early with adequate systemic antiviral (acyclovir) and corticosteroids treatment, which caused improving of the clinical findings and visual acuity as well. In 2 patients, pars plana vitrectomy was performed. Despite the long-lasting chronic combined medication, during the follow-up period in these 2 patients the decrease of the visual acuity occurred.ARN is very rare, vision-threatening viral disease. The appearance of 3 cases of ARN at a local hospital is unusual. The diagnosis may be established according to the characteristic clinical findings and to its development. To determine the pathogen (varicella zoster virus in 70 %, herpes simplex virus in almost 30 %, and cytomegalovirus very rarely) is not critical for the diagnosis establishment. The early use of specific virostatic drugs is the key assumption for optimal ARN treatment, as it happened in our patients. Contrary to the adequate treatment, retinal complications may occur, and often, even after successful pars plana vitrectomy, the decrease of visual functions is possible. For the ophthalmologic practice, it is important to remember, that in case of ARN suspicion, it is urgent to start the virostatic treatment and to add corticosteroids not earlier than after 24-48 hours. In case of complications, it is necessary to contact the specialized vitreoretinal center immediately. It is necessary to inform the patient about very serious condition of the infected eye and its uncertain prognosis contrary to the adequate treatment, and about the danger to the opposite eye in case of delay of missing treatment. In case of herpetic anterior uveitis, the fundus examination, including the periphery of the retina is important.