Depending on how you blur the definition of 'institution' either the Imperial House of Japan[1] or the Jewish Kehuna[2] might qualify. Some more candidates here

Depending on how you blur the definition of 'institution' either the Imperial House of Japan[1] or the Jewish Kehuna[2] might qualify. Some more candidates here: http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Miscellaneous/2008_November_18#Second_oldest_organization_in_the_world http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archiv... [1] http://en.wikipedia.org/wiki/Imperial_House_of_Japan http://en.wikipedia.org/wiki/Imperial_House_of_Japan [2] http://en.wikipedia.org/wiki/Kohen http://en.wikipedia.org/wiki/Kohen