Streptococcal infections are suggested as a risk factor for narcolepsy. This hypothesis is supported by the presence of anti-streptolysin antibodies in 65% of patients with narcolepsy. These infections are associated with the activation of general immunity and concomitant increased permeability of blood-brain barrier after T cell activation during inflammation and fever. It has also been shown a significant association between birth order and narcolepsy in genetically susceptible patients, with positivity for HLA-DQB1⁎0602 allele. Watson and colleagues showed a significant association between birth order and narcolepsy in genetically susceptible patients, with positivity for HLA-DQB1⁎0602 allele. In that study, the disease was predominant in young children cases compared to controls. We report here the case of a child diagnosed with narcolepsy with cataplexy, positivity for the HLA-DQB1⁎0602 and previous history of streptococcal infection.