Family name ประเสริฐสิทธิ์ (ประเสริฐสิทธิ์ 
, Prasertsit 
, Prahsertsit ) , all over the world, is a rare surname. The surname ประเสริฐสิทธิ์ is characteristic of Thailand, where it is quite a rare surname, Malaysia, where it is a very rare surname, and the United States, where it is an extremely rare surname. Much less frequently, ประเสริฐสิทธิ์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| ประเสริฐสิทธิ์, Prahsertsit | Thailand |
| Prasertsit | United States, Malaysia, Thailand |