Narcolepsy type 1 (NT1) is a unique central sleepiness disorder that affects individuals with excessive daytime sleepiness (EDS), cataplexy, sleep paralysis, and hypnagogic hallucinations. The etiology and pathogenesis of NT1 remains unclear, although some viral infections are thought to be related to NT1. This paper reports an unusual case of late-onset NT1 with human immunodeficiency virus (HIV) infection and antiretroviral therapy for five years. The relationship between HIV infection, immune, Immune reconstitution inflammatory syndrome (IRIS) and NT1 should be further investigated, as excessive daytime sleepiness is more common in HIV-infected patients than in the general population.