Infection with the varicella-zoster virus (VZV) is very common worldwide and is one of the main causes of infectious encephalitis. Immunosuppressed patients are at increased risk of severe disease and central nervous system (CNS) involvement. We report the case of a 43-year-old man with HIV infection and poor adherence to antiretroviral therapy who presented to the emergency department (ER) with complaints of diplopia and a frontal headache, referring to having a child with chickenpox. Brain magnetic resonance imaging revealed three hyperintense T2-weighted lesions surrounded by edema in the right sublenticular, left occipital and left parietal regions, and VZV DNA was detected in the cerebrospinal fluid (CSF). After admitting the diagnosis of VZV encephalitis, the patient was treated with intravenous acyclovir, with clinical improvement and a favorable outcome.