Japanese encephalitis is the single largest cause of viral encephalitis in the world today. It occurs in yearly post monsoon outbreaks in Uttar Pradesh and other parts of India and south east Asia. There is presently no antiviral drug of proven benefit for this illness and treatment is mostly supportive. The drug Ribavirin is already in the market in use for other indications. It has been found useful in West Nile encephalitis and various hemorrhagic fevers caused by related arboviruses. This is a double blind placebo of Ribavirin in Japanese encephalitis. To the best of our knowledge, this is the first such trial in the world. The study hypothesis is that children treated with ribavirin will be no different from those getting placebo in terms of mortality, length of hospital stay, days to return to consciousness and oral feeds, days to become afebrile and convulsion free and in 3 month sequelae rate.