OBJECTIVES: Identify clinical features, findings on CT and MRI of the brain and the determination of herpes virus 1, 2 and 6 in cerebrospinal fluid (CSF) by Western Blot test and PCR. METHODS: Was performed on all patients admitted to the Department of Neurology Specialty Hospital National Medical Center Century XXI, IMSS, in the period of March 2009 on the date 2011 that date who had symptoms and signs related acute herpes encephalitis.  A clinical history and complete neurological examination were realized. Was obtained by lumbar puncture for cytochemical cerebrospinal fluid, cytological, culture, Herpes antigens 1, 2, 6 and precipitated DNA was obtained by PCR for the determination. RESULTS: Twelve patients positive for herpes virus 1, 2 and 6. The most outstanding neurological characteristics of these patients were: headache in 10 of the 12 patients, (83%) and confuse state in 10 of the 12 patients,  (83%), in the CSF, was identified lymphocytic pleocytosis  in all the patients in a range of 7 a 500 cells an average value of 110, high protein in all patients from 38 to 322 mg/dl range an average 124.4. The main findings in CT and RM were bilateral hypodensity, multifocal extratemporal injury and ventricular dilatation and magnetic resonance signal change in temporal or extratemporal regions with enhancement in lesions, all patients were treated with acliclovir. At follow-up at 6 months: No reported deaths and major sequelae secondary symptomatic epilepsy and mild cognitive impaire CONCLUSIONS: The herpes virus positive patients 1,2 and 6 show an early diagnosis of encephalitis and remains an urgent neurological identify characteristics and initiate early comprehensive management including acyclovir to reduce morbidity and mortality in this patient group.