Klein-Levin syndrome (KLS) is a rare disease characterized by recurrent episodes of hypersomnia and cognitive and behavioral dysfunction. In addition, all functions remain intact during the intermittent period. Infection is a common risk factor for its onset. In this case, a 17-year-old patient with KLS was admitted to our hospital in March 2023 who first developed KLS symptoms and relapsed after being infected with influenza A Virus (H1N1). Based on the typical symptoms occurred during the patient′s attack, the absence of symptoms and signs during the interval, and the absence of other triggers, the patient was diagnosed with KLS recurrence secondary to influenza A Virus (H1N1). This case report aims to reveal that influenza A Virus (H1N1) may be contribute to the recurrence of KLS and that preventing infection is important in the treatment of KLS to draw the attention of clinical physicians.