Eight patients with herpetic encephalitis (HE) and one patient with herpetic meningitis were investigated. The clinical and laboratory investigations (CR, EEG, and others) are described. In all the cases the diagnosis was corroborated with serological and virological tests unraveling the herpes simplex virus. A high-sensitive diagnose the atypical HE cases with subacute and chronic course that is important for correct treatment.