Surname Phommasen (Phommasen 
) , in the entire world, is a rare last name. The cognomen Phommasen is habitual in Laos, where it is quite a common surname, Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phommasen | Thailand, United States, Laos |
| soulasen phommasen swimmer, LA (b. 1992) |
|