Last name เพชรใหญ่ (เพชรใหญ่, Pechyai, Petchyai 
) , in the world, is an extremely rare surname. The last name เพชรใหญ่ is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Petchyai | Thailand |