Family name ประสิทธฺ์ (ประสิทธฺ์ 
) , all over the world, is an extremely rare surname. The cognomen ประสิทธฺ์ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname. More prevalently, ประสิทธฺ์ is the forename as well as the last name.