The infections due to herpes viruses are widely spread, people being every day at high risk of contamination starting early age. The characteristic of the herpes virus infection consists of a symptom less evolution following the prime infection. As for any other herpetic infection, episodes infection exacerbation is due to some determining factors. Clinical symptom in herpes virus infection varies according to the virus type, age of the patient and site. Oral signs and symptoms are numerous, extremely intense and often, difficult to diagnose. Progressing in so many ways and being diagnosed and treated by so many medical specialties it is difficult to evaluate the actual number of cases. Consequently it is mandatory to train dentists in order to be able to accurately diagnose and treat the herpetic infection and to prevent nosocomial cross infections in dental office.