Cognomen Piriu (Piriu 
) , throughout the world, is a rare surname. The family name Piriu is characteristic of Romania, where it is quite a rare surname, Greece, where it is a very rare surname, and Spain, where it is an extremely rare surname. Not in comparison with a country's population, it most frequently occurs in Romania, Greece, and Germany. Very seldom, Piriu is the forename as well as the last name.