To draw attention to this relatively common disease, which may cause major visual function impairment, and to present our own experience in the diagnosis, treatment and follow-up of acute retinal necrosis patients.The manifestation, detection, treatment options and complications of unilateral acute retinal necrosis are illustrated by six case reports.Five patients were immunocompetent, whereas the sixth one suffered from chronic leukemia. In two patients the disease developed in association with herpes zoster, whereas the remaining four showed no signs of herpes disease. Systemic therapy with acyclovir, corticosteroids, salicylates and photocoagulation produced favorable response in five patients. Therapy had to be discontinued in leukemia patient for complications, which resulted in the disease recurrence with retinal detachment and proliferative vitreoretinopathy. Other patients remained stable with preserved visual function and only minor complications.In all six patients, the accurate diagnosis was reached relatively late. Obviously, anterior uveitis alone attracted ophthalmologists' attention, and their diagnostic and therapeutic efforts had mostly been focused on anterior uveitis impairment in the visual acuity developed. Appropriate therapy with virostatics, which is necessary in the treatment of this disease, was introduced relatively late, however, all patients responded favorably to this therapy, which also held for the immunocompromised patients administered a half usual dose of acyclovir. Our experience confirmed that virostatic therapy for acute retinal necrosis should be administered for at least 6 weeks. Retinal photocoagulation for prevention of rhegmatogenous retinal detachment appers to be beneficial, as this type of retinal detachment did not develop in these patients. The patient who did not undergo laser photocoagulation of retina did not develop rhegmatogenous retinal detachment but did develop proliferative vitreoretinopathy.Acute retinal necrosis is a relatively common disease affecting visual function, which occurs in both immunocompetent and immunocompromised subjects. The disease with its typical clinical picture and many complications should be taken in consideration on the differential diagnosis of uveitis. Therapy for acute retinal necrosis is complex, long-term and associated with frequent systemic complications that may threaten the patient's general health status.