Cognomen เพียรธัญญกิจ (เพียรธัญญกิจ 
) , around the world, is an extremely rare last name. The family name เพียรธัญญกิจ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| เพียรธัญญกิจ | Thailand |