Family name ไพโรจน์ธนกูล (ไพโรจน์ธนกูล 
) , all around the world, is an extremely rare last name. The cognomen ไพโรจน์ธนกูล is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| ไพโรจน์ธนกูล | Thailand |