The article gives the clinical case of herpes simplex encephalitis relapse with the resistant seizures in a child. What we describe is a clinical approach towards the differential diagnostic of the seizures in structural epilepsy, which are resistant to anticonvulsants, or late herpes simplex encephalitis relapse. Good clinical perspective may be the indication of the intratecal synthesis of the IgG-specific antibodies to the herpes simplex type 1 and 2. Conducting etiotropic treatment with the appointment of acyclovir and pathogenetic therapy with the use of Cytoflavin contributed to the rapid and stable remission of epileptic seizures and regression of neurological deficit.