To report a case of acyclovir-induced acute renal failure (ARF) suspected as acute retinal necrosis syndrome.

The authors report a 55-year-old male patient who presented with left eye visual disturbance due to suspected acute retinal necrosis syndrome. Non-oliguric ARF developed after the infusion of intravenous acyclovir (850 mg every 8 hours). The patient did not show any uremic symptoms or signs. The crystal was not discovered in the urine. After stopping the acyclovir infusion and hydration, acyclovir-induced ARF was reversed.

Although possessing critical nephrotoxicity, acyclovir is a useful antiviral drug. Therefore, when using acyclovir, the importance of hydration and preventing acyclovir-induced ARF should be considered.