Cognomen Lertwajana (Lertwajana 
) , across the world, is a very rare family name. The cognomen Lertwajana is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Lertwajana | Thailand |
Pichaya, Phanasathon, Peeraphol, Phasuthon, and Phossathon