Last name ปฐมโรจนวงศ์ (ปฐมโรจนวงศ์ 
) , in the entire world, is an extremely rare family name. The cognomen ปฐมโรจนวงศ์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| ปฐมโรจนวงศ์ | Thailand |