Subacute sclerosing pan encephalitis (SSPE) is a rare neurodegenerative disorder related to a persistent and aberrant measles virus infection. It is associated with poor prognosis and high mortality. We report a case of a seven-year-old boy who manifested the disease despite proper vaccination and with no documented past history of measles. The case is being reported for its atypical presentation, rarity and its possibility of occurrence in young vaccinated subjects, possibly due to undocumented pre-vaccination measles infection.