Cognomen Itthidech (Itthidech 
) , worldwide, is an extremely rare last name. The family name Itthidech is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname. Much more prevalently, Itthidech is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Itthidech | Thailand |
Saejiw, Srisuwan, Phophang, Punantapong, Chuaykerd, and Amornthanis