Last name ประเสริฐศิริ (ประเสริฐศิริ 
) , in all the world, is a very rare cognomen. The last name ประเสริฐศิริ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, ประเสริฐศิริ is the forename as well as the last name.